Abstract: A lasing device includes an active layer comprising a cholesteric liquid crystal material and a laser dye, and a liquid crystal cell including spaced apart substrates defining a cell gap in which the active layer is disposed. The substrates include electrodes arranged to bias the active layer into an oblique helicoidal (ChOH) state. At least one substrate of the liquid crystal cell is optically transparent for a lasing wavelength range of the device.

Abstract: A combination of microvalves and waveguides may enable the creation of reconfigurable on-chip light sources compatible with planar sample preparation and particle sensing architecture using either single-mode or multi-mode interference (MMI) waveguides. A first type of light source is a DFB laser source with lateral gratings created by the light valves. Moreover, feedback for creating a narrowband light source does not have to be a DFB grating in the active region. A DBR configuration (Bragg mirrors on one or both ends of the active region) or simple mirrors at the end of the cavity can also be used. Alternately, ring resonators may be created using a valve coupled to a bus waveguide where the active gain medium is either incorporated in the ring or inside an enclosed fluid. The active light source may be activated by moving a fluid trap and/or a solid-core optical component defining its active region.

Abstract: Disclosed are photonic particles and methods of using particles in biological samples. The particles are configured to emit laser light when energetically stimulated by, e.g., a pump source. The particles may include a gain medium with inorganic materials, an optical cavity with high refractive index, and a coating with organic materials. The particles may be smaller than 3 microns along their longest axes. The particles may attach to each other to form, e.g., doublets and triplets. The particles may be injection-locked by coupling an injection beam into a particle while pumping so that an injection seed is amplified to develop into laser oscillation. A microscopy system may include a pump source, beam scanner, spectrometer with resolution of less than 1 nanometer and acquisition rate of more than 1 kilohertz, and spectral analyzer configured to distinguish spectral peaks of laser output from broadband background.

Abstract: A method of generating a light-matter hybrid species of charged polaritons at room temperature includes providing an organic semiconductor microcavity being a doped organic semiconductor sandwiched in a microcavity capable of generating an optical resonance and coupling light to the polaron optical transition in the organic semiconductor microcavity thereby forming polaron-polaritons. The doped organic semiconductor may be a hole/electron transport material having a polaron absorption coefficient exceeding 102 cm?1 and capable of generating a polaron optical transition with a linewidth smaller than a predetermined threshold. The optical resonance of the microcavity has a resonance frequency matched with the polaron optical transition.

Abstract: A package that includes a container and a container closure having a vacuum-indicating pull tab. The container includes a longitudinal axis extending therethrough, a mouth, and a sealing surface. The container closure includes a seal membrane sealingly and removably coupled to the container sealing surface to seal the container, and a pull tab configured to extend from the seal membrane. Manipulation of the pull tab provides an indication of the presence or absence of a vacuum in the package.

Abstract: The invention provides a solid state dye laser and methods for preparing the solid state dye laser. The solid state dye laser includes a porous copolymer membrane of poly(vinylidenefloride-cohexafluoroproplyne (PVDF-HFP) and a laser dye. The laser dye is incorporated in pores of the copolymer membrane. The solid state dye laser is prepared using one of a phase inversion technique, a phase separation technique, and a breath figure technique.

Abstract: A signs-of-deterioration detector for a semiconductor laser includes a first light receiving section that acquires first information relating to an optical output of the semiconductor laser and a second light receiving section that acquires second information relating to an intensity distribution of the emission pattern below the lasing threshold of the semiconductor laser. The detector also includes a holding section that holds the first information and the second information at a predetermined time point T1. The detector further includes a deciding section that decides the presence or absence of signs of rapid decrease of the optical output of the semiconductor laser by comparing the first information and the second information at at least one time point Tn (T1<Tn), with those at the time point T1.

Abstract: This invention provides compounds of formula IA or IB: wherein HY, R1, R2, G1, W, n, and A are as described in the specification. The compounds are inhibitors of PI3K and/or mTor and are thus useful for treating proliferative, inflammatory, or cardiovascular disorders.

Abstract: The invention provides light-emitting compositions, including lasing and fluorescent compositions. The invention particularly relates to programmable biological substrates, which fluoresce and/or lase, and which have a wide variety of different applications. The invention extends to use of the fluorescent compositions and lasing compositions comprising programmable biological substrates in fabricating lasers, and in various biological imaging applications, such as in assays.

Abstract: The transition metal complex is represented by Formula (1) [where M represents a transition metal element; K and L each represent a monodentate or bidentate ligand; m and o each represent an integer from 0 to 5; n represents an integer from 1 to 3; X, Y, R1, R2, and R4 each represent a hydrogen atom, alkyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl, aralkyl, alkenyl, alkynyl, or alkoxy; R3 represents a hydrogen atom, alkyl, cycloalkyl, heterocycloalkyl, aryl, aralkyl, heteroaryl, alkenyl, alkynyl, aryloxy, or alkoxy having two or more carbon atoms; and A represents alkyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl, aralkyl, alkenyl, alkynyl, or alkoxy].

Abstract: The challenge of providing a long-life solid-state dye laser medium is tackled. This challenge is solved by a solid-state dye laser medium comprising a polydimethylsiloxane, and a dye dissolved in the polydimethylsiloxane. The dye is preferably a pyrromethene dye.

Abstract: A plasmonic laser device has resonant nanocavities filled with a gain medium containing an organic dye. The resonant plasmon frequencies of the nanocavities are tuned to align with both the absorption and emission spectra of the dye.

Abstract: An organic dye laser produces a continuous-wave (cw) output without any moving parts (e.g., without using flowing dye streams or spinning discs of solid-state dye media to prevent photobleaching) and with a pump beam that is stationary with respect to the organic dye medium. The laser's resonant cavity, organic dye medium, and pump beam are configured to excite a lasing transition over a time scale longer than the associated decay lifetimes in the organic dye medium without photobleaching the organic dye medium. Because the organic dye medium does not photobleach when operating in this manner, it may be pumped continuously so as to emit a cw output beam. In some examples, operation in this manner lowers the lasing threshold (e.g., to only a few Watts per square centimeter), thereby facilitating electrical pumping for cw operation.

Abstract: The invention relates to a light source, comprising an optical resonator (1) and an optical medium (2) arranged therein that can be excited so as to emit light, wherein the optical medium (2) comprises at least one two-level system, in particular a two-level system that is not population-inverted, having an at least metastable lower state, and the optical length of the resonator (1) comprising at least one curved mirror (1) is selected such that the free spectral bandwidth of the resonator is equal to or greater than the absorption bandwidth and/or fluorescence bandwidth of the optical medium (2) and only a single longitudinal mode and a plurality of transversal modes of the resonator (1) are arranged within the fluorescence bandwidth.

Abstract: Disclosed is a transition metal complex represented by the following formula (1): (wherein M represents a transition metal element; K represents an uncharged monodentate or bidentate ligand; L represents a monodentate or bidentate monoanionic or dianionic ligand; m and o represent an integer from 0 to 5; n represents an integer from 1 to 3; p represents an integer from 0 to 4; W— represents a counterion; and Y1 to Y4, R1, and R2 each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, a heterocycloalkyl group, an aryl group, an aralkyl group, a heteroaryl group, an alkenyl group, an alkynyl group, or an alkoxy group).

Abstract: A luminescent material includes transition metal complex comprising a ligand in which an electron density of a p orbital of a highest occupied molecular orbital level is higher than 0.239 and lower than 0.711 when the electron density is calculated according to quantum chemical calculation (Gaussian09/DFT/RB3LYP/6-31G), the p orbital being in the outermost shell of an element coordinated to the metal.

Abstract: The present invention relates to a solid dye resonator, and to a solid dye laser hand piece comprising same. The solid dye resonator comprises: solid dye; a high-reflection mirror; an output coupler; a first mounting plate on which the high-reflection mirror is mounted; a second mounting plate which is spaced apart from the first mounting plate and which has a surface on which the output coupler is mounted; a driving motor mounted on the first mounting plate, such that a motor shaft is directed toward the second mounting plate; and a rotary shaft interposed between the first mounting plate and the second mounting plate, and connected to the motor shaft of the driving motor such that the rotary shaft interlockingly rotates with the rotation of the driving motor.

Abstract: The laser includes an optical fiber including a cavity containing a microfluidic gain medium bounded by a composite structure of alternating layers of high and low index materials forming an axially invariant, rotationally symmetric photonic bandgap cavity. The optical fiber also includes at least one microfluidic channel containing liquid crystal modulators in the fiber cladding extending in an axial direction and further includes a pair of electrodes flanking the microfluidic channel. An electrical potential across the pair of electrodes will rotate the liquid crystal molecules to rotate the linearly polarized state of light emitted from the cavity. An external linear polarizer is disposed around the fiber to modulate azimuthal laser intensity distribution.

Abstract: To reduce the laser threshold by efficiently exciting a light-emitting body in a solid-state dye laser with light having high density, thereby facilitating emission of laser beams, and to miniaturize a solid-state dye laser including an excitation light source. A solid-state dye laser capable of emitting laser beams by efficiently introducing light from an excitation light source to a light-emitting body incorporated in an optical resonator structure and exciting the light-emitting body with light with high density, is realized.

Abstract: Compositions capable of simultaneous two-photon absorption and higher order absorptivities are provided. Compounds having a donor-pi-donor or acceptor-pi-acceptor structure are of particular interest, where the donor is an electron donating group, acceptor is an electron accepting group, and pi is a pi bridge linking the donor and/or acceptor groups. The pi bridge may additionally be substituted with electron donating or withdrawing groups to alter the absorptive wavelength of the structure. Also disclosed are methods of generating an excited state of such compounds through optical stimulation with light using simultaneous absorption of photons of energies individually insufficient to achieve an excited state of the compound, but capable of doing so upon simultaneous absorption of two or more such photons. Applications employing such methods are also provided, including controlled polymerization achieved through focusing of the light source(s) used.

Abstract: The present invention relates to a solid dye resonator, and to a solid dye laser hand piece comprising same. The solid dye resonator comprises: solid dye; a high-reflection mirror; an output coupler; a first mounting plate on which the high-reflection mirror is mounted; a second mounting plate which is spaced apart from the first mounting plate and which has a surface on which the output coupler is mounted; a driving motor mounted on the first mounting plate, such that a motor shaft is directed toward the second mounting plate; and a rotary shaft interposed between the first mounting plate and the second mounting plate, and connected to the motor shaft of the driving motor such that the rotary shaft interlockingly rotates with the rotation of the driving motor.

Abstract: A solid-state laser emitting material for use in conjunction with a light source includes a polymer matrix functioning as host materials, containing laser dye of rhodamine 590 or rhodamine 610 as gain materials and nano-submicron particles as scatters therein. The lowest lasing threshold of the laser emitting material is approximately 5 mJ/cm2 for 585 nm emission and 2 mJ/cm2 for 630 nm emission.

Abstract: The present invention relates to organic lasers. More specifically, the present invention is directed to an organic laser that provides a self-stimulated source of coherent radiation originating from organic microcavity polaritons. The organic polariton laser of the present invention comprises a substrate, a resonant microcavity comprising an organic polariton emission layer; and an optical pump. In preferred embodiments the optical pump is a microcavity OLED allowing for the fabrication of a self-contained or integrated device.

Abstract: Embodiments disclosed herein relate to a laser die. The laser die includes a base epitaxial portion, a mesa portion, and first and second facets, wherein at least one of the first and second facets is flared such that an area of the facet is increased. Embodiments disclosed herein also relate to a high-speed laser. The high-speed laser includes a substrate, an active region positioned above the substrate, a mesa positioned above the active region, and one or more facets, wherein at least one of the one or more facets includes a flared portion configured to increase an area of the facet.

Abstract: The present invention generally relates to lasers comprising fluidic channels, such as microfluidic channels. In some instances, the channel contains two or more fluids. The fluids may remain non-mixed within the channel, for example, due to immiscibility and/or laminar flow within the channel. The fluids may be arranged in the channel such that light propagating in a first fluid is prevented by the second fluid from exiting the first fluid, for example, due to differences in the indexes of refraction (e.g., causing internal reflection of the fluid to occur). Thus, in one embodiment, a first fluid may be at least partially surrounded by a second fluid having a second index of refraction lower than the index of refraction of the first fluid. In some embodiments, the fluidic channel is used as a laser, for instance, a dye laser, i.e., a laser created by directing light at a dye to produce coherent light. The dye may be present in one or more fluids within the fluidic channel.

Abstract: A laser oscillation element 1 according to the invention comprises a cholesteric liquid crystal layer 2 containing cholesteric liquid crystals, a cholesteric liquid crystal layer 3 containing cholesteric liquid crystals facing the cholesteric liquid crystal layer 2, and a defect layer 4 containing a dye 5 which emits fluorescence upon optical excitation disposed between the cholesteric liquid crystal layers 2, 3. A selective reflection wavelength band in the cholesteric liquid crystals overlaps with the emission band of the fluorescence emitted by the dye 5, the helical winding directions of the cholesteric liquid crystals contained in the cholesteric liquid crystal layers 2, 3 are identical, and the transition moments of the dye 5 are aligned parallel to the surfaces of the cholesteric liquid crystal layers 2, 3. According to the laser oscillation element 1, a laser oscillation can be generated with high efficiency. Moreover, continuous wave lasing can be generated.

Abstract: A method for generating a laser output signal includes the steps of: generating an optical pump signal that is a sequence optical pulses each having a duration of about n?f, where ?f represents a flourescence lifetime of a laser dye and 3?n?25; directing the optical pump signal into an optical resonant cavity having a laser dye gain element that contains the laser dye for transforming the optical pump signal into an excited optical signal; resonating the excited optical signal in the optical resonant cavity; and emitting a portion of the excited optical signal from the optical resonant cavity.

Abstract: The invention relates to a microfluidic dye laser including a pump light source configured to provide light having a pump light wavelength. The microfluidic dye laser also includes an elastomer substantially optically transparent at the pump light wavelength and at a microfluidic dye laser wavelength. A microfluidic channel configured to accept a fluidic dye is defined in the elastomer. An optical grating is formed in a single mode 3D waveguide in the microfluidic channel in order to provide a single mode microfluidic dye laser light as output in response to illumination with light from the pump light source. In another aspect, the invention features a method of tuning a wavelength of a microfluidic dye laser light by mechanically deforming the elastomeric laser chip to change the grating period in the optical cavity.

Abstract: There are disclosed compounds for assisting triplet absorption in a laser, such as a pulsed-dye laser, the compounds comprising at least one molecule chosen from nitroxides and nitrones. In one embodiment, the disclosed compounds may be mixed with the dye of a dye laser in an amount sufficient to assist in triplet absorption. In one embodiment, the nitroxide compound comprises tempol[4-hydroxy-2,2,6,6-tetramethyl-piperidinyloxy, free radical]. Also disclosed are methods of using the disclosed compounds to control the triplet absorption of a dye laser or improve the performance or life span of a gaseous or solid laser.

Abstract: The present invention relates to a method and system of generating backward stimulated Rayleigh-Bragg scattering by focusing activating radiation through a multi-photon absorbing dye solution, thereby producing coherent output radiation with no measured frequency shift and measured pump threshold values independent of the spectral line width of the input activating radiation.

Abstract: To reduce the laser threshold by efficiently exciting a light-emitting body in a solid-state dye laser with light having high density, thereby facilitating emission of laser beams, and to miniaturize a solid-state dye laser including an excitation light source. A solid-state dye laser capable of emitting laser beams by efficiently introducing light from an excitation light source to a light-emitting body incorporated in an optical resonator structure and exciting the light-emitting body with light with high density, is realized.

Abstract: A solid-state laser emitting material for use in conjunction with a light source includes a polymer matrix functioning as host materials, containing laser dye of rhodamine 590 or rhodamine 610 as gain materials and nano-submicron particles as scatters therein. The lowest lasing threshold of the laser emitting material is approximately 5 mJ/cm2 for 585 nm emission and 2 mJ/cm2 for 630 nm emission.

Abstract: There are disclosed compounds for assisting triplet absorption in a laser, such as a pulsed-dye laser, the compounds comprising at least one molecule chosen from nitroxides and nitrones. In one embodiment, the disclosed compounds may be mixed with the dye of a dye laser in an amount sufficient to assist in triplet absorption. In one embodiment, the nitroxide compound comprises tempol [4-hydroxy-2,2,6,6-tetramethyl-piperidinyloxy, free radical]. Also disclosed are methods of using the disclosed compounds to control the triplet absorption of a dye laser or improve the performance or life span of a gaseous or solid laser.

Abstract: Although having been used for conventional dye laser solvents, organic solvents have a disadvantage of volatility and inflammability, which makes a dye laser device large and cumbersome. In the present invention, which has been developed to solve this problem, an ionic liquid is used as the dye laser solvent. An organic dye stably dissolves in an ionic liquid and the light-emitting property is almost comparable to the case where an organic solvent is used. Since ionic liquids do not have volatility and inflammability, the dye laser medium according to the present invention is extremely easy to handle. In addition, it also has a property that the photobleach is extremely low compared to conventional dye laser mediums using an organic solvent as the solvent thereof. It is easy to obtain a laser sensor for detecting a predetermined specimen with high sensitivity using the dye laser medium according to the present invention.

Abstract: The present invention relates to a laser gain medium comprising at least one active species adapted to be stimulated to emit laser light within a predetermined wavelength range and optical feedback means defining a resonator for said laser light. The feedback means comprise at least one substantially solid cholesteric layer having a substantially planar texture exhibiting selective reflection of light defined by a reflection band tuned to said predetermined wavelength range.

Abstract: To provide a DFB solid-state dye laser including a grating having Moire interference fringes. A DFB solid-state dye laser element includes: a laser medium containing an organic dye; and a distribution feedback type resonance unit having a third grating including a Moire fringe corresponding to an overlap between a first grating and a second grating formed in different directions. The third grating including a Moire fringe is formed by irradiating a photoresist with a laser for two-beam interference exposure, and then rotating a substrate by a predetermined angle and re-irradiating the substrate with the laser.

Abstract: The invention relates to a microfluidic dye laser including a pump light source configured to provide light having a pump light wavelength. The microfluidic dye laser also includes an elastomer substantially optically transparent at the pump light wavelength and at a microfluidic dye laser wavelength. A microfluidic channel configured to accept a fluidic dye is defined in the elastomer. An optical grating is formed in a single mode 3D waveguide in the microfluidic channel in order to provide a single mode microfluidic dye laser light as output in response to illumination with light from the pump light source. In another aspect, the invention features a method of tuning a wavelength of a microfluidic dye laser light by mechanically deforming the elastomeric laser chip to change the grating period in the optical cavity.

Abstract: A semiconductor laser diode that internally converts one or more short wavelength “pump” beams to an output beam at a longer wavelength using nonlinear optical frequency conversion in the semiconductor. Modal phase matching of the pump and output beams in a semiconductor waveguide allows the conversion process to proceed with high efficiency.

Abstract: An efficient technique for producing deterministically polarized single photons uses liquid-crystal hosts of either monomeric or oligomeric/polymeric form to preferentially align the single emitters for maximum excitation efficiency. Deterministic molecular alignment also provides deterministically polarized output photons; using planar-aligned cholesteric liquid crystal hosts as 1-D photonic-band-gap microcavities tunable to the emitter fluorescence band to increase source efficiency, using liquid crystal technology to prevent emitter bleaching. Emitters comprise soluble dyes, inorganic nanocrystals or trivalent rare-earth chelates.

Abstract: A method of minimizing contamination of optical components of a laser resonator is disclosed. The resonator components are located in an enclosure, which may contain contaminants including water vapor and organic favor released by the optical components, mounts of the optical components, or the enclosure itself. The enclosure may also contain suspended particulate matter. In order to reduce the level of these contaminants, a purging system extracts gas from the enclosure and passes the gas through a desiccant, an organic vapor trapping material, and a particulate matter filter then returns the extracted gas to the enclosure. The purging system is particularly useful for ultrafast lasers and ultraviolet lasers where the power of the laser radiation increases the probability of destabilizing reactions between laser radiation and contaminants.

Abstract: A laser package includes a submount, a laser die mounted on the submount, a lid mounted on the submount over the laser die, and a soft metal disposed between the laser die and the lid, wherein the soft metal conducts heat between the laser die and the lid. The soft metal is able to creep or cold flow under pressure to accommodate for varying manufacturing tolerances and varying thermal expansion rates of the elements in the laser package.

Abstract: The present invention relates to an amplifying medium for solid-state dye lasers and to a solid-state dye laser provided with an amplifying medium of this type. The amplifying medium according to the invention comprises an essentially solid active medium which contains at least one type of activatable particle which can be excited to emit laser light in a certain wavelength range, and optical feedback means which define a resonator for the laser light, where the feedback means comprise an essentially solid feedback medium which has a periodic structure. The feedback medium in the amplifying medium is a polymeric dispersion film having a crystalline structure which comprises, in particular, core/shell particles which can be formed into a film.

Abstract: Use of spiro compounds of formula (I), where K1 and K2 are, independently of one another, conjugated systems, as a laser dye.

Abstract: A thin-film organic laser, that includes: a substrate; a bottom mirror provided on the substrate; at least one active region deposited on the bottom mirror, wherein the at least one active region includes organic gain material; an external mirror provided at a predetermined distance from the at least one active region such that the bottom mirror combined with the external mirror forms a laser resonator; and an optical pumping means for exciting the organic gain material to produce a laser beam with a wavelength ? and at least one lateral laser mode in the laser resonator and an output of laser light.

Abstract: An organic laser cavity device, that includes: a first dielectric stack for receiving and transmitting pumped beam light and being reflective to laser light over a predetermined range of wavelengths and having a substantially low threshold for optical excitation; an organic active region for receiving the transmitted pumped beam light and laser light from the first dielectric stack, and emits the laser light; a second dielectric stack for reflecting the transmitted pumped beam light and the laser light from the organic active region back into the organic active region, wherein a combination of the first and second dielectric stacks and the organic active region outputs the laser light; and an external self-contained photon source of the pumped beam light cooperating with the organic laser cavity for optical excitation at the substantially low threshold.

Abstract: An organic vertical cavity laser light producing device includes a bottom dielectric stack reflective to light over a predetermined range of wavelengths; an organic active region for producing laser light, and having an organic active region including emissive material; and a top dielectric stack spaced from the bottom dielectric stack and reflective to light over a predetermined range of wavelengths. Pump-beam light is transmitted and introduced into the organic active region through at least one of the dielectric stacks. The organic active region includes one or more periodic gain region(s) and organic spacer layers disposed on either side of the periodic gain region(s) and arranged so that the periodic gain region(s) is aligned with the antinodes of the device's standing wave electromagnetic field, and wherein the spacer layers are substantially transparent to the laser light.

Abstract: A vertical cavity organic laser device, that includes: an organic laser cavity including: a bottom dielectric stack for receiving and transmitting pump beam light and being reflective to laser light over a predetermined range of wavelengths; an organic active region for receiving transmitted pump beam light from the bottom dielectric stack and for emitting the laser light; a top dielectric stack for reflecting transmitted pump beam light and laser light from the organic active region back into the organic active region, wherein a combination of the bottom and the top dielectric stacks and the organic active region produces the laser light; the device further including an external pump beam light source for optically pumping light to the organic laser cavity; and a positioner for locating the organic laser cavity in a spaced relationship to the external pump beam light source.

Abstract: High-efficiency laser-like emission at low thresholds in dipolar organic materials upon pulsed optical excitation, without using any external mirrors. Unusually high conversion efficiencies and low thresholds in laser-like emission have been observed in the solutions of organic molecular salts having large dipole moments and specific dye molecules having high photoluminescence efficiencies. Pumped with frequency-doubled pulses from a Nd:YAG laser, conversion efficiencies in the range of 15-40% were achieved without incorporation of external mirrors. The threshold pump energies for such emission have been observed to be low (<8 ?J). The spectrally narrowed output beam was found to have low divergence, high degree of polarization, and pulse-width less than that of the excitation pulses (50 picoseconds).

Abstract: A controllable single-photon source having a single illuminated molecule in a condensed phase host is provided. The single molecule is illuminated with a pulse of radiation having a wavelength such that the molecule is excited to a vibrational state higher in energy than an associated excited electronic state. The molecule rapidly, incoherently and irreversibly decays, with a lifetime Tvib, from the vibrational state to the excited electronic state by transferring the corresponding vibrational energy to the host. The excited electronic state has a lifetime T, and with high probability the single molecule makes a radiative transition from this state to emit a single photon. The pump pulse duration Tp satisfies the condition Tvib<Tp<T. Room temperature operation and spectral separation of pump and single-photon radiation are thereby provided. A semiconductor nanocrystal can be used instead of a molecule.

Abstract: A method of minimizing contamination of optical components of a laser resonator is disclosed. The resonator components are located in an enclosure, which may contain contaminants including water vapor and organic favor released by the optical components, mounts of the optical components, or the enclosure itself. The enclosure may also contain suspended particulate matter. In order to reduce the level of these contaminants, a purging system extracts gas from the enclosure and passes the gas through a desiccant, an organic vapor trapping material, and a particulate matter filter then returns the extracted gas to the enclosure. The purging system is particularly useful for ultrafast lasers and ultraviolet lasers where the power of the laser radiation increases the probability of destabilizing reactions between laser radiation and contaminants.