Abstract: A system includes a laser configured to generate a pump beam at a pump wavelength. The system also includes a multi-media Raman resonator configured to receive the pump beam and generate an output beam. The multi-media Raman resonator includes multiple mirrors and multiple Raman media optically located between the minors. Output power in the output beam is spectrally concentrated around a single dominant wavelength that is longer than a pump wavelength. The longer wavelength of the output beam is associated with a combination of at least one Stokes shift associated with each of the individual Raman media. A filter could be configured to absorb light at a wavelength that is absorbed by one of the Raman media or to redirect light at the wavelength absorbed by one of the Raman media away from that Raman medium.

Abstract: A low-power “all-in-one” Yb/Raman optical fiber laser system includes a pump input, and a Yb/Raman resonator including a segment of integrated Yb/Raman fiber configured to provide both a ionic gain and Raman gain. A set of input gratings and output gratings define a series of reflector pairs that, together with the integrated Yb/Raman fiber, create a nested series of cavities that provide a stepwise transition from the input wavelength to a selected target output wavelength.

Abstract: A laser apparatus for producing mode locked pulses includes a closed optical system adapted to connect to a fiber grain medium to form a laser cavity. The fiber gain medium is adapted to receive pulses characterized by a first state and to output pulses characterized by a second state. The closed optical system is adapted to receive the pulses in the second state and output pulses in a state similar to the first state.

Abstract: In one embodiment, the instant invention provides a method that includes: outputting a first laser beam having: a beam quality factor (M2) between 1 and 5, and a spectral width of less than 0.15 nm, where the outputting is performed by a laser generating component that includes a alexandrite laser oscillator; converting the first laser beam through a first Raman cell to produce a second laser beam, where the first Raman cell is filled with a first gas; and converting the second laser beam through a second Raman cell to produce a final laser beam, where the second Raman cell is filled with a second gas and is operationally positioned after the first Raman cell, where the first gas and the second gas are different gasses, and where the final laser beam having: a second energy of at least 1 mJ, and at least one wavelength longer than 2.5 micron.

Abstract: Embodiments described herein include a system for producing ultrashort tunable pulses based on ultra broadband OPA or OPG in nonlinear materials. The system parameters such as the nonlinear material, pump wavelengths, quasi-phase matching periods, and temperatures can be selected to utilize the intrinsic dispersion relations for such material to produce bandwidth limited or nearly bandwidth limited pulse compression. Compact high average power sources of short optical pulses tunable in the wavelength range of 1800 to 2100 nm and after frequency doubling in the wavelength range of 900 to 1050 nm can be used as a pump for the ultra broadband OPA or OPG. In certain embodiments, these short pump pulses are obtained from an Er fiber oscillator at about 1550 nm, amplified in Er fiber, Raman-shifted to 1800 to 2100 nm, stretched in a fiber stretcher, and amplified in Tm-doped fiber.

Abstract: A method of generating high-power laser output in the 1100 to 1500 um spectral region having a controllable linewidth. A Raman amplifier comprised of one or more nested pairs of fiber Bragg grating cavities tuned to the 1st, 2nd, . . . N?1st order Stokes wavelengths is seeded with both the desired Nth order Stokes output wavelength and the corresponding zeroth-order Stokes pump wavelength. As the pump wavelength propagates through the apparatus, it is sequentially converted to the 1st, 2nd, . . . N?1st order Stokes wavelengths in the nested fiber Bragg grating cavities. The desired Nth order Stokes output wavelength is then amplified by the N?1st Stokes order as it propagates through the nested fiber Bragg grating cavities. The linewidths of various Stokes orders can be controlled through adjusting resonant bandwidths of the fiber Bragg grating cavities by offsetting, through heating, the reflectivity bandwidths of each pair of cavity gratings.

Abstract: A method to increase the output power of monolithic narrow-linewidth Yb-doped fiber amplifiers by suppressing simulated Brillouin scattering. The fiber amplifier employs a co-propagating geometry and is seeded with broad- (source 2) and narrow- (source 1) linewidth signals that are sufficiently different in wavelengths to allow for efficient gain competition and favorable temperature profile at the output end of fiber. The broadband seed signal possesses the higher emission and absorption cross sections. If source 2 is also given sufficiently greater input power than source 1, it will be amplified to its maximum value as the seed signals reach the middle portion of the gain fiber. Beyond that portion, the signal having the lower emission and absorption cross sections (signal 1) will continue to experience gain by power transfer from both signal 2 and the pump light, attaining a power output well beyond what the maximum output would have been had the amplifier been illuminated with a single frequency beam.

Abstract: A saturable absorber (SA) is constructed using a fiber taper embedded in a carbon nanotube/polymer composite. A fiber taper is made by heating and pulling a small part of standard optical fiber. At the taper's waist light is guided by the glass-air interface, with an evanescent field protruding out of the taper. Carbon nanotubes mixed with an appropriate polymer host material are then wrapped around the fiber taper to interact with the evanescent field. Saturable absorption is possible due to the unique optical properties of the carbon nanotubes. The device can be used in mode-locked lasers where it initiates and stabilizes the pulses circulating around the laser cavity. The SA can be used in various laser cavities, and can enable different pulse evolutions such as solitons, self-similar pulses and dissipative solitons. Other applications include but are not limited to optical switching, pulse cleanup and pulse compression.

Abstract: A mid- to far-infrared solid state Raman laser system comprising a resonator cavity comprising: an input reflector adapted to be highly transmissive for light with a first wavelength in the range of about 3 to about 7.5 micrometers for admitting the first beam to the resonator cavity; and an output reflector adapted to be partially transmissive for light with a second wave-length greater than about 5.5 micrometers for resonating the second wavelength in the resonator and for outputting an output beam, the input reflector further being adapted to be highly reflective at the second wavelength for resonating the second wave-length in the resonator; and a solid state diamond Raman material located in the resonator cavity for Raman shifting the pump beam and generating the second wavelength.

Abstract: A continuous wave Raman laser for producing visible laser output comprising: a resonator cavity; at least a first reflector and a second reflector said first and second reflectors being located at opposite ends of the resonator cavity; a laser gain medium located in the resonator cavity for generating a continuous wave fundamental beam which resonates within the resonator cavity when pumped by a pump beam from a pump source external to the resonator cavity; a solid Raman-active medium positioned in the resonator cavity for Raman shifting the fundamental beam to produce a continuous wave Raman beam which resonates within the resonator cavity; and a non-linear medium positioned in the resonator cavity for frequency converting the continuous wave Raman beam to a converted wavelength to produce a continuous wave converted beam.

Abstract: In one embodiment, the instant invention provides a method that includes: outputting a first laser beam having: a beam quality factor (M2) between 1 and 5, and a spectral width of less than 0.15 nm, where the outputting is performed by a laser generating component that includes a alexandrite laser oscillator; converting the first laser beam through a first Raman cell to produce a second laser beam, where the first Raman cell is filled with a first gas; and converting the second laser beam through a second Raman cell to produce a final laser beam, where the second Raman cell is filled with a second gas and is operationally positioned after the first Raman cell, where the first gas and the second gas are different gasses, and where the final laser beam having: a second energy of at least 1 mJ, and at least one wavelength longer than 2.5 micron.

Abstract: A laser apparatus for producing mode locked pulses includes a closed optical system adapted to connect to a fibre grain medium to form a laser cavity. The fibre gain medium is adapted to receive pulses characterized by a first state and to output pulses characterized by a second state. The closed optical system is adapted to receive the pulses in the second state and output pulses in a state similar to the first state.

Abstract: A Raman laser system, the system comprising a resonator cavity comprising a plurality of reflectors, wherein at least one reflector is an output reflector adapted for outputting a pulsed output beam from the resonator cavity at a frequency corresponding to a Raman shifted frequency of the pump beam, wherein the output reflector is partially transmitting at the Raman-converted frequency; a solid state Raman-active medium located in the resonator cavity to be pumped by a pulsed pump beam having a pump repetition rate and for Raman-converting a pump pulse incident on the Raman-active medium to a resonating pulse at a Raman-converted frequency resonating in the resonator cavity; a resonator adjuster for adjusting the optical length of the resonator to match the round-trip time of the resonating Raman-converted pulse with the pump beam repetition rate such that the resonating pulse is coincident both temporally and spatially with a pump pulse in the Raman-active medium on each round trip, to Raman amplify the reso

Abstract: A method and a laser system for generating a pulsed laser signal with a laser signal wavelength and a laser signal repetition rate, the laser system includes a fiber laser unit includes a cladding pumped fiber laser includes a fiber laser light guiding region surrounded by a pump cladding, the fiber laser light guiding region includes at least one active element; at least one pump laser unit for launching a pump signal into the cladding pumped fiber laser, the pump signal unit includes at least one pump diode emitting a signal at a pump signal wavelength; and a modulating unit for modulating the pump signal into a plurality of pump pulses.

Abstract: Optical devices include a doped glass material in which the dopant facilitates the transmission of energy out from the glass material. The doped glass may not significantly absorb a selected wavelength of laser radiation to be manipulated by the optical devices. The dopant may comprise one or more of a transition metal element, an actinide element, and a lanthanide element. Laser systems include at least one such optical device and a laser device configured to emit a beam to be manipulated by the optical device. Methods for forming optical devices and laser systems including such optical devices include dispersing a dopant within a glass material to form, and forming the glass material into a body having a size and shape configured to manipulate a beam of radiation emitted by a laser device. The dopant is selected to comprise a material that facilitates the transmission of energy out from the glass material.

Abstract: A laser cooling system includes a substrate, an REO layer of single crystal rare earth oxide including at least one rare earth element positioned on the surface of the substrate, and an active layer of single crystal semiconductor material positioned on the REO layer to form a semiconductor-on-insulator (SOI) device. Light guiding structure is at least partially formed by the REO layer so as to introduce energy elements into the REO layer and produce cooling by anti-Stokes fluorescence. The active layer of single crystal semiconductor material is positioned on the REO layer in proximity to the light guiding structure so as to receive the cooling.

Abstract: A laser structure is provided that includes a pulsed source producing a pulsed signal having a low spontaneous noise component to its spectral output and a pulse-shape that is optimally flat. Also, the laser structure includes one or more optical fiber structures receiving the pulsed signal and performing Raman amplification. The pulsed signal is used to excite in the one or more optical fiber structures possessing normal chromatic dispersion, which acts as a nonlinear system for efficient mid-infrared spectral generation.

Abstract: A Raman laser device includes: an amplifying medium (2) absorbent at a pump wavelength ?P and emitting at an excitation wavelength ?S, a Raman medium (3) exhibiting at least one Stokes shift ??R, such as to convert the emission at the excitation wavelength ?S into a continuous emission at a Raman wavelength ?R. The amplifying medium and the Raman medium belong to a Raman cavity resonant at the excitation wavelength ?S and at the Raman wavelength ?R. The length of the Raman medium is less than 9 mm and the sum of the gaps between each of the elements of the Raman cavity is less than 2 mm. A system including such a Raman laser device, and a method of adjusting the Raman laser device are described.

Abstract: Embodiments described herein include a system for producing ultrashort tunable pulses based on ultra broadband OPA or OPG in nonlinear materials. The system parameters such as the nonlinear material, pump wavelengths, quasi-phase matching periods, and temperatures can be selected to utilize the intrinsic dispersion relations for such material to produce bandwidth limited or nearly bandwidth limited pulse compression. Compact high average power sources of short optical pulses tunable in the wavelength range of 1800-2100 nm and after frequency doubling in the wavelength range of 900-1050 nm can be used as a pump for the ultra broadband OPA or OPG. In certain embodiments, these short pump pulses are obtained from an Er fiber oscillator at about 1550 nm, amplified in Er fiber, Raman-shifted to 1800-2100 nm, stretched in a fiber stretcher, and amplified in Tm-doped fiber.

Abstract: A laser apparatus includes a plurality of pumps each of which is configured to emit a corresponding pump laser beam having a unique peak wavelength. The laser apparatus includes a spectral beam combiner configured to combine the corresponding pump laser beams into a substantially spatially-coherent pump laser beam having a pump spectrum that includes the unique peak wavelengths, and first and second selectively reflective elements spaced from each other to define a lasing cavity including a lasing medium therein. The lasing medium generates a plurality of gain spectra responsive to absorbing the pump laser beam. Each gain spectrum corresponds to a respective one of the unique peak wavelengths of the substantially spatially-coherent pump laser beam and partially overlaps with all other ones of the gain spectra. The reflective elements are configured to promote emission of a laser beam from the lasing medium with a peak wavelength common to each gain spectrum.

Abstract: A system and method for converting a pulsed beam of irradiation from a laser operating at a first wavelength to a pulsed beam of irradiation at a second, Stokes, wavelength. The system includes two Raman cells filled with the same Raman-active gas. The second cell receives a backward-propagating Stokes pulse beam from the first Raman cell, with the backward-propagating Stokes pulsed beam entering the second Raman cell in a direction opposite to the direction of travel of the incoming laser pulses at the first wavelength. The second Raman cell generates a high intensity output pulsed beam at the second, Stokes, wavelength. The system can produce a high intensity eye-safe pulsed beam.

Abstract: Provided is a fiber laser device capable of preventing laser light from damaging a laser oscillator even if the laser light is reflected by an object to be irradiated or at an output end.

Abstract: A modular, compact and widely tunable laser system for the efficient generation of high peak and high average power ultrashort pulses. Modularity is ensured by the implementation of interchangeable amplifier components. System compactness is ensured by employing efficient fiber amplifiers, directly or indirectly pumped by diode lasers. Peak power handling capability of the fiber amplifiers is expanded by using optimized pulse shapes, as well as dispersively broadened pulses. Dispersive broadening is introduced by dispersive pulse stretching in the presence of self-phase modulation and gain, resulting in the formation of high-power parabolic pulses. In addition, dispersive broadening is also introduced by simple fiber delay lines or chirped fiber gratings, resulting in a further increase of the energy handling ability of the fiber amplifiers.

Abstract: A pulsed laser system may include a Raman fiber that is configured to act as multiple wavelength Raman laser. The fiber is configured to receive a pulsed input beam from an input source and convert the input beam to an output beam having narrow band outputs at first and second frequencies v1 and v2.

Abstract: Provided herein are certain embodiments of systems, methods and devices for Raman lasers based on micro-ring and mircro-racetrack resonators, and the manufacturing thereof. For example, a device can be provided which is structured to receive an electro-magnetic radiation including a resonator arrangement which has a distance from one edge thereof to another edge thereof of at most approximately a wavelength of the electro-magnetic radiation that impacts the resonator arrangement. According to some embodiments, the resonator arrangement can be configured to generate a Raman radiation when impacted by a further electro-magnetic radiation. In some embodiments, the resonator arrangement can solely generate the Raman radiation which is lasing, which Raman radiation can be generated by the resonator arrangement in a continuous mode and/or a pulsed lasing mode. The resonator arrangement can generate the Raman radiation which is lasing without a use of an external electrical driver.

Abstract: A mid-infrared system for optical probing is disclosed that comprises a mid-infrared fiber laser based on cascaded Raman wavelength shifting, a sample volume, and a detector or detection system. The cascaded Raman wavelength shifting process in optical fibers involves the emission of a plurality of optical phonons for at least some of the pump photonics involved in the process. As one example, using the cascaded Raman wavelength shifting process a pump laser wavelength between 1 and 2 ?m can be shifted down to between 2.5 to 10 ?m. In one embodiment, the mid-infrared fiber laser comprises a pump laser with a wavelength between 1 and 2 ?m, one or more stages of cascaded Raman oscillators implemented in fused silica fiber, and one or more stages of cascaded Raman oscillators implemented in mid-infrared fiber that transmits beyond 2 ?m. Examples of mid-infrared fibers include chalcogenides, fluorides and tellurite fibers.

Abstract: A multimode optical fiber has a core that includes radially dependent dopant materials to provide a desired refractive index profile and a desired Raman gain coefficient profile. A laser diode pump laser array provides high brightness light that is launched into the fiber and is subject to maximum Raman gain along the optical axis, thereby favoring the lowest order mode of the fiber, discriminating against higher order modes and providing a high brightness, diffraction limited output. The fiber can be incorporated into oscillators, amplifiers and other optical devices.

Abstract: Techniques and apparatus for using stimulated Raman scattering in an optical gain medium to produce amplified laser pulses.

Abstract: Single crystal diamond material produced using chemical vapour deposition (CVD), and particularly diamond material having properties suitable for use in optical applications such as lasers, is disclosed. In particular, a CVD single crystal diamond material having preferred characteristics of longest linear internal dimension, birefringence and absorption coefficient, when measured at room temperature, is disclosed. Uses of the diamond material, including in a Raman laser, and methods of producing the diamond are also disclosed.

Abstract: Cladding-pumped Raman fiber lasers and amplifiers provide high-efficiency conversion efficiency at high brightness enhancement. Differential loss is applied to both single-pass configurations appropriate for pulsed amplification and laser oscillator configurations applied to high average power cw source generation.

Abstract: The present invention relates in particular to the field of lasers and in particular to a laser source having a neodymium-doped crystal (2; 23) or fiber and pumpable by pumping means (3; 25) and a non-linear Raman effect converter stimulated in methane (4; 32), characterized in that the crystal (2; 23) or fiber pumped by said pumping means (3; 25) is able to emit a laser radiation at a wavelength between 1.31 and 1.36 ?m and in that the Raman converter (4; 32) is able to convert the radiation generated by the crystal (2; 23) or by the fiber into at least one second radiation (7; 36) with a wavelength between 2 and 2.3 ?m.

Abstract: A multimode-fiber Raman laser includes a pump source configured to provide optical radiation centered at a pump wavelength and characterized by a spectral bandwidth greater than 100 MHz and an oscillator resonant at an emission wavelength greater than the pump wavelength. The oscillator includes an input coupler optically aligned with the pump source and a multimode optical fiber optically coupled to the input coupler. The multimode optical fiber includes an input section having a fiber Bragg grating, an intracavity section of a predetermined length optically coupled to the input section, and an output section having a fiber Bragg grating. The oscillator also includes an output coupler optically coupled to the multimode optical fiber and configured to provide a laser output at the emission wavelength.

Abstract: The invention provides a cascade Raman laser including a pumping laser light source that generates pumping light, a cascade Raman resonator having an input-side optical reflector that receives the pumping light and selectively reflects light of each wavelength corresponding to a n-th Stokes ray (n is an integer more than 1) of Raman scattering to the pumping light, a Raman optical fiber that is connected to the input-side optical reflector and generates Raman scattering light at least by the pumping light and an output-side optical reflector that is connected to the Raman optical fiber and selectively reflects light of each wavelength corresponding to the n-th Stokes ray and a blocking device interposed between the pumping laser light source and the cascade Raman resonator and blocks the first Stokes ray generated within the cascade Raman resonator from entering the pumping laser light source side.

Abstract: A powerful fiber laser system is configured with at least one filtering element capable of preventing a backreflected Raman component of the main signal from propagating along the upstream stretch of the system. The filtering element includes a slanted fiber grating, one or more cladding formations disposed in a cladding of fiber and having a refractive index greater than that one of the cladding, but lower than a refractive index of the core, and/or a combination of two spaced apart single mode fibers and a low mode fiber spliced to the opposing ends of the respective SM fibers.

Abstract: In one aspect, a signal processing system includes a processor, an I/O device operatively associated with the processor, and a memory device bearing instructions configured to cause the processor to obtain a representation of signal data over a data domain and position a sliding-window over a portion of the signal data, such portion corresponding to a sliding-window domain, to analyze the signal data within the sliding-window domain to detect the presence of a signature multiplet and, based on the analysis of the data, to estimate the pedestal of the signal data within the sliding-window domain.

Abstract: Devices and methods for providing stimulated Raman lasing are provided. In some embodiments, devices include a photonic crystal that includes a layer of silicon having a lattice of holes and a linear defect that forms a waveguide configured to receive pump light and output Stokes light through Raman scattering, wherein the thickness of the layer of silicon, the spacing of the lattice of holes, and the size of the holes are dimensioned to provide Raman lasing. In some embodiments, methods include forming a layer of silicon, and etching the layer of silicon to form a lattice of holes with a linear defect that forms a waveguide configured to receive pump light and output Stokes light through Raman scattering, wherein the thickness of the layer of silicon, the spacing of the lattice of holes, and the size of the holes are dimensioned to provide Raman lasing.

Abstract: A Raman shifter is provided with improved optical efficiency and robustness, particularly for high power applications. In one embodiment, a source system (100) includes a source pump laser (102) and a seed laser (104). Beams from the pump laser (102) and seed laser (104) combine for transmission into a Raman cell (112). Folding optics define a multi-pass pathway through the Raman cell (112). Such folding optics may include an internal reflectance element. An entry window into the Raman cell, an exit window from the Raman cell, and the internal reflectance elements include surfaces disposed at a Brewster angle relative to the incident beam. The Raman cell medium is circulated in a direction transverse to the beam pathways through the cell. In this manner, improved optical efficiency and robustness is achieved as well as improved performance over a significant wavelength band.

Abstract: The invention relates to a method for stabilizing the spectrum of a pulsed coherent optical source that comprises controlling the offset frequency ?0 and the repetition rate ?r in order to stabilize the frequencies of the comb lines constituting the optical spectrum thereof. The method comprises forming, from the pulsed coherent optical source (S1), a beam that is directed onto a reference resonant optical cavity (CR), and using the signal generated by the reference resonant optical cavity (CR) for controlling the offset frequency ?o or the repetition rate ?r, and probing, using a comb line, an atomic or molecular transition (AMT) in order to generate a driving signal for the repetition rate ?r or the offset frequency ?0.

Abstract: A device for generating a laser light beam includes a module. The module includes at least one laser light source, and a mechanical, an electrical and/or an optical interface defined towards an outside of the module.

Abstract: The invention provides a cascade Raman laser including a pumping laser light source that generates pumping light, a cascade Raman resonator having an input-side optical reflector that receives the pumping light and selectively reflects light of each wavelength corresponding to a n-th Stokes ray (n is an integer more than 1) of Raman scattering to the pumping light, a Raman optical fiber that is connected to the input-side optical reflector and generates Raman scattering light at least by the pumping light and an output-side optical reflector that is connected to the Raman optical fiber and selectively reflects light of each wavelength corresponding to the n-th Stokes ray and a blocking device interposed between the pumping laser light source and the cascade Raman resonator and blocks the first Stokes ray generated within the cascade Raman resonator from entering the pumping laser light source side.

Abstract: The invention concerns a laser system with a frequency comb generator for generating a comb of optical frequencies having an offset frequency and a plurality of equidistant modes. The laser system further preferably includes at least one stabilizer for stabilizing the frequency comb onto a certain offset frequency and/or onto a certain mode spacing. The laser system further includes an optical amplifier for amplifying the frequency comb coupled out of the frequency comb generator, the amplification factor of this amplifier being variable; and the amplifier is followed by a Raman medium for generating a Raman shift of the frequency comb.

Abstract: A method to increase the output power of narrow-linewidth rare earth-doped fiber amplifiers by suppressing simulated Brillouin scattering. The fiber amplifier is seeded with two or more lasers having frequencies and input powers that are sufficiently different. The seed signal with the highest emission cross section (e.g., signal 2) initially experiences the greatest gain. If signal 2 is also given sufficiently greater input power than signal 1, it will be amplified to its maximum value before the seed signals have reached the midpoint of the gain fiber. Beyond that point, the signal having the lower emission and absorption cross sections (signal 1) and significantly lower input power will continue to experience gain by power transfer from both signal 2 and the pump light, attaining a power output well beyond what the maximum output would have been had the amplifier been illuminated with a single frequency beam.

Abstract: An optical communication system includes a gain medium that receives optical signal(s) of one or more optical signal wavelengths. The system also includes pump source(s) that are capable of generating at least a first pump signal and a second pump signal. The first pump signal includes at least one integer Raman order wavelength that includes a Raman gain peak that is one stokes shift away from at least one of the one or more optical signal wavelengths. The second pump signal includes at least one fractional Raman order pump wavelength that includes a Raman gain peak that is a non-integer multiple of a stokes shift from each of the one or more optical signal wavelengths. Optionally, there might be one or more other pump signals that do not satisfy the criteria specified for the first pump signal or the second pump signal.

Abstract: A powerful fiber laser system is configured with at least one filtering element capable of preventing a backreflected Raman component of the main signal from propagating along the upstream stretch of the system. The filtering element includes a slanted fiber grating, one or more cladding formations disposed in a cladding of fiber and having a refractive index greater than that one of the cladding, but lower than a refractive index of the core, and/or a combination of two spaced apart single mode fibers and a low mode fiber spliced to the opposing ends of the respective SM fibers.

Abstract: Raman molecular imaging is used to differentiate between normal and diseased cells or tissue. For instance benign and malignant lesions of bladder and other tissues can be distinguished, including epithelial tissues such as lung, prostate, kidney, breast, and colon, and non-epithelial tissues, such as bone marrow and brain. Raman scattering data relevant to the disease state of cells or tissue can be combined with visual image data to produce hybrid images which depict both a magnified view of the cellular structures and information relating to the disease state of the individual cells in the field of view.

Abstract: A continuous wave Raman laser for producing visible laser output comprising: a resonator cavity; at least a first reflector and a second reflector said first and second reflectors being located at opposite ends of the resonator cavity; a laser gain medium located in the resonator cavity for generating a continuous wave fundamental beam which resonates within the resonator cavity when pumped by a pump beam from a pump source external to the resonator cavity; a solid Raman-active medium positioned in the resonator cavity for Raman shifting the fundamental beam to produce a continuous wave Raman beam which resonates within the resonator cavity; and a non-linear medium positioned in the resonator cavity for frequency converting the continuous wave Raman beam to a converted wavelength to produce a continuous wave converted beam.

Abstract: An optical wave generator comprising a first-level Raman sideband generator (RSBG). The first-level RSBG comprises a first hollow-core photonic crystal fibre HCPCF (203) arranged to be filled with a Raman active gas and a first two-pump continuous wave (CW) laser source (200) having a first pump laser beam (201) at a first frequency and a second pump laser beam (202) at a second frequency, the laser source being arranged to excite the first HCPCF to generate a Raman sideband spectrum comprising a first plurality of spectral components.

Abstract: A mid-infrared system for optical probing is disclosed that comprises a mid-infrared fiber laser based on cascaded Raman wavelength shifting, a sample volume, and a detector or detection system. The cascaded Raman wavelength shifting process in optical fibers involves the emission of a plurality of optical phonons for at least some of the pump photonics involved in the process. As one example, using the cascaded Raman wavelength shifting process a pump laser wavelength between 1 and 2 ?m can be shifted down to between 2.5 to 10 ?m. In one embodiment, the mid-infrared fiber laser comprises a pump laser with a wavelength between 1 and 2 ?m, one or more stages of cascaded Raman oscillators implemented in fused silica fiber, and one or more stages of cascaded Raman oscillators implemented in mid-infrared fiber that transmits beyond 2 ?m. Examples of mid-infrared fibers include chalcogenides, fluorides and tellurite fibers.

Abstract: This fiber laser is provided with: a signal light source that outputs a signal light; a rare earth-doped fiber that amplifies and outputs the signal light from the signal light source; a Raman amplifying fiber that is routed as a portion of an optical transmission path in order to output the output light from the rare earth-doped fiber to an outside thereof; and a wavelength selecting element that is provided in the optical transmission path from the Raman amplifying fiber to the signal light source and does not allow transmission of a Stokes light that is generated in the Raman amplifying fiber.

Abstract: The invention is in the field of laser radiation generation in bands II and III, and relates to a device for generating laser radiation in the infrared having means for modifying the amplified-radiation frequency and using the Raman effect, characterized by additionally having at least one diode able to emit laser radiation in the 1.8-2.1 ?m frequency range, at least one current generator able to generate current levels at an adjustable repetition rate, means for supplying said current levels to said diode, and means for amplifying the laser radiation emitted by said diode and comprised of at least one fiber doped with an ion having laser activity in the diode emission range.