Abstract: An optical amplifier module is configured as a multi-stage free-space optics arrangement, including at least an input stage and an output stage. The actual amplification is provided by a separate fiber-based component coupled to the module. A propagating optical input signal and pump light are provided to the input stage, with the amplified optical signal exiting the output stage. The necessary operations performed on the signal within each stage are provided by directing free-space beams through discrete optical components. The utilization of discrete optical components and free-space beams significantly reduces the number of fiber splices and other types of coupling connections required in prior art amplifier modules, allowing for an automated process to create a “pluggable” optical amplifier module of small form factor proportions.

Abstract: A method includes applying a boost pump signal to a pump laser of a laser system based on a preceding off duration associated with the laser system, and applying a forward pump signal to the pump laser. A laser system includes a seed laser situated to generate seed optical pulses, a pump laser situated to generate pump optical radiation, a fiber amplifier situated to receive the pump optical radiation and the seed optical pulses, and a controller situated to select a pump boost duration or pump boost magnitude based on an off duration associated with the laser system.

Abstract: A distributed Raman amplifier comprises a loss-measuring device that measures losses in an optical fiber transmission line; a signal processing circuit that compares the measured losses to a threshold, below which a pumping light source is permitted to pump the transmission line; a control circuit responsive to a control signal from the signal processing circuit for controlling operation of the pumping light source; and a spool of fiber configurable to be optically coupled between the pumping light source and optical point-loss sources in the transmission line when the losses are above the threshold. The spool of fiber has a fiber of sufficient length to offset aggregated losses, which prevents the distributed Raman amplifier from shutting down while also allowing the distributed Raman amplifier to achieve entitled gain by pumping the fiber in the spool.

Abstract: A solid-state optical amplifier is described, having an active core and doped cladding in a single chip. An active optical core runs through a doped cladding in a structure formed on a substrate. A light emitting structure, such as an LED, is formed within and/or adjacent to the optical core. The cladding is doped, for example, with erbium or other rare-earth elements or metals. Several exemplary devices and methods of their formation are given.

Abstract: A titanium nitride-based metamaterial, and method for producing the same, is disclosed, consisting of ultrathin, smooth, and alternating layers of a plasmonic titanium nitride (TiN) material and a dielectric material, grown on a substrate to form a superlattice. The dielectric material is made of A1-xScxN, where ‘x’ ranges in value from 0.2 to 0.4. The layers of alternating material have sharp interfaces, and each layer can range from 1-20 nanometers in thickness. Metamaterials based on titanium TiN, a novel plasmonic building block, have many applications including, but not ‘limited to emission enhancers, computer security, etc. The use of nitrogen vacancy centers in diamond, and light emitting diode (LED) efficiency enhancement is of particular interest.

Abstract: The present disclosure relates to a fiber encapsulation mechanism for energy dissipation in a fiber amplifying system. One example embodiment includes an optical fiber amplifier. The optical fiber amplifier includes an optical fiber that includes a gain medium, as well as a polymer layer that at least partially surrounds the optical fiber. The polymer layer is optically transparent. In addition, the optical fiber amplifier includes a pump source. Optical pumping by the pump source amplifies optical signals in the optical fiber and generates excess heat and excess photons. The optical fiber amplifier additionally includes a heatsink layer disposed adjacent to the polymer layer. The heatsink layer conducts the excess heat away from the optical fiber. Further, the optical fiber amplifier includes an optically transparent layer disposed adjacent to the polymer layer. The optically transparent layer transmits the excess photons away from the optical fiber.

Abstract: A system includes a first actuatable apparatus of an optical source, the first actuatable apparatus being altered within a range of values about a target value to thereby alter a spectral feature of the light beam; a second actuatable apparatus of the optical source, the second actuatable apparatus being altered to thereby alter the spectral feature of the light beam; a metrology system including an observation system configured to output an indication of a deviation between the actual value at which the first actuatable apparatus is operating and the target value; and a control system configured to determine whether the deviation is greater than an acceptable deviation, and, if it is greater than the acceptable deviation, then send a signal to a second actuation module controlling the second actuatable apparatus to adjust the actual value at which the first actuatable apparatus is operating to be closer to the target value.

Abstract: An optical transceiver that includes an optical modulator of a Mach-Zehnder type and made of primarily semiconductor materials, and an Erbium Doped Fiber Amplifier (fiber amplifier) is disclosed. The fiber amplifier and the MZ modulator, in addition to a wavelength tunable laser diode, an intelligent coherent receiver, and a polarization maintaining splitter, are installed within a compact case following the standard of CFP2. The fiber amplifier provides a wavelength tunable filter that passes light amplified by the fiber amplifier but eliminates amplified spontaneous emission in regions out of the wavelength band of the light.

Abstract: The embodiments of the present invention disclose a method and an apparatus for determining a gain of a Raman optical amplifier and a Raman optical amplifier. The method includes: acquiring present gain parameter information of a Raman optical amplifier; and determining a present gain of a monitoring channel of the Raman optical amplifier according to the present gain parameter information and a correspondence between a gain of the monitoring channel of the Raman optical amplifier and gain parameter information. According to the method and apparatus for determining a gain of a Raman optical amplifier and the Raman optical amplifier that are in embodiments of the present invention, a present gain of a monitoring channel can be accurately determined; therefore, a gain spectrum of the Raman optical amplifier can be accurately monitored, and the gain of the Raman optical amplifier can be accurately adjusted to a target gain.

Abstract: A method (10) of changing operating mode of an optical amplifier in an amplifier chain in an optical network, the optical amplifier initially configured to operate in a first mode to apply a substantially constant first gain to an optical signal comprising a plurality of optical channels, the method comprising, after a time period unique to the optical amplifier within the amplifier chain (12), configuring the optical amplifier to operate in a second mode to apply a second gain to the optical signal so that the optical power of the optical signal is maintained at a target optical power dependent on a current plurality of optical channels in the optical signal (14).

Abstract: A bi-directionally pumped PM fiber amplifier includes an amplifier input coupled to a first WDM coupler and a second WDM coupler providing an amplifier output. A doped fiber is between the WDM couplers. A first pump light source emitting at a first wavelength along a first polarization axis is coupled to the WDM coupler through a polarization beam combiner/splitter and a polarization rotator is for downstream pumping of the doped fiber with rotated light relative to the first polarization. The fiber is upstream pumped with light having the first polarization using a second pump light source emitting at the first wavelength/first polarization, by an output of an optical power splitter with its input coupled to the first pump light source, or by a fiber-coupled rotator mirror coupled to the second WDM coupler.

Abstract: A fiber temperature control assembly comprising a spool holding element adapted to hold a fiber spool and a compression element adapted to press fiber windings of a doped optical fiber wound around the fiber spool against said spool holding element being in thermal contact with a heating and/or cooling element of said fiber temperature control assembly.

Abstract: Example photoconductive devices and example methods for using photoconductive devices are described. An example method may include providing a photoconductive device having a metal-semiconductor-metal structure. The method may also include controlling, based on a first input state, illumination of the photoconductive device by a first optical beam during a time period, and controlling, based on a second input state, illumination of the photoconductive device by a second optical beam during the time period. Further, the method may include detecting an amount of current produced by the photoconductive device during the time period, and based on the detected amount of current, providing an output indicative of the first input state and the second input state. The example devices can be used individually as discrete components or in integrated circuits for memory or logic applications.

Abstract: A multipass fiber amplifier comprises a micro-optic-module polarization separating device including a first ASE blocking device, a micro-optic-module 90° polarization rotating reflector including a second ASE blocking device, a pump source for providing pump light; a micro-optic-module wavelength-division multiplexer (WDM) for combining the pump light and the laser beam; and a gain fiber having a first end and a second end for amplifying the laser beam using the pump light, where the first ASE blocking device is coupled to the first end of the gain fiber and the second ASE blocking device is coupled to the second end of the gain fiber.

Abstract: A photonic integrated circuit is presented that includes a substrate, and a first and second waveguide patterned on the substrate. The first waveguide guides an input beam of radiation. The photonic integrated circuit also includes a coupling region, wherein the first and second waveguides each pass through the coupling region. One or more modulating elements are coupled to each of the first and second waveguides. The first waveguide and the second waveguide have a first facet and a second facet, respectively, and first and second reflections are generated at the first and second facets within the first and second waveguides, respectively. The one or more modulating elements coupled to each of the first and second waveguides are designed to adjust the phase of the first and second reflections before the first and second reflections pass through the coupling region.

Abstract: The present application is directed to a planar waveguide amplifier. The planar waveguide amplifier includes a substrate having an upper surface and a lower surface. The planar waveguide amplifier includes a core formed on an upper surface of the substrate. The core includes a channel configured to transmit light there through. The planar waveguide amplifier also includes an upper cladding layer formed above the core. The upper cladding layer includes a glass doped with rare earth material in an amount less than about 5% of the upper cladding layer. The application is also directed to a method of amplifying a signal.

Abstract: A remote optically pumped amplifier in a multi-span optical communications link. A backwards Raman pump module performs backwards Raman amplification in an optical communications span that contains the remote optically pumped amplifier. A residual amount of backwards Raman pump power is then used to power the remote optically pumped amplifier. The remote optically pumped amplifier may be located 40 to 120 kilometers in optical distance from the backwards Raman pump module such that at least three milliwatts of residual Raman pump power is received by the remote optically pumped amplifier. The Raman pump module may be a multi-pump Raman pump module. A controller controls pump power provided by at least one of the pumps of the backwards Raman pump module, so as to at least partially compensate for optical signal strength versus wavelength variation introduced by the remote optically pumped amplifier and the backwards Raman pump module.

Abstract: A fiber coupled modular laser system comprises a laser oscillator, at least one fiber pre-amplifier, and at least one free space solid state power amplifier. The output of the laser oscillator is fiber coupled with the input of the at least one fiber pre-amplifier or the at least one free space solid state power amplifier. The output or the input of the at least one fiber pre-amplifier is fiber coupled with the input or the output of the at least one free space solid state power amplifier.

Abstract: A tunable transmission optical filter is optically coupled between a laser section and semiconductor optical amplifier (SOA) section of a tunable laser device. The optical filter may be tuned to provide a high transmission near the lasing peak while suppressing a significant portion of back-propagating amplified spontaneous emission (ASE) of the SOA section. Without the optical filter, the laser output spectrum may develop side lobes of higher intensity after the ASE is amplified and reflected in the forward direction by the laser gain and mirror sections. While lessening the side lobes, the optical filter simultaneously transmits the laser peak for amplification by the SOA section.

Abstract: A hybrid fiber amplifier and method of adjusting gain and gain slope of thereof. The hybrid fiber amplifier comprises: RFA and EDFA that does not comprise variable optical attenuator. The RFA comprises pump signal combiner, pump laser group, out-of-band narrow-band filter, and photodetector. The EDFA comprises input coupler, erbium-doped fiber, output coupler, input photodetector, and output photodetector that are connected in sequence. The hybrid fiber amplifier also comprises control module that coordinates and controls EDFA and/or RFA to adjust gain and/or the gain slope based on desired amplification requirements. The EDFA and/or RFA can be coordinated and controlled by using the control module to achieve desired amplification effect. In addition, the EDFA does not comprise the variable optical attenuator, which avoids problems caused by the variable optical attenuator.