A coherent light source provides spontaneous emission (Dicke superradiance/subradiance) using a dilute and optically thin cloud of disordered atoms. The coherent light source provides improved noise statistics over that of a laser and, accordingly, may be used in sensitive interferometric applications such as light gyroscopes.

Gaseous laser systems and related techniques are disclosed. Techniques disclosed herein may be utilized, in accordance with some embodiments, in providing a gaseous laser system with a configuration that provides (A) pump illumination with distinct edge surfaces for an extended depth and (B) an output beam illumination from a resonator cavity with distinct edges in its reflectivity profile, thereby providing (C) pump beam and output beam illumination on a volume so that the distinct edge surfaces of its pump and beam illumination are shared-edge surfaces with (D) further edge surfaces of the amplifier volume at the surfaces illuminated directly by the pump or output beams, as defined by optical windows and (optionally) by one or more flowing gas curtains depleted of the alkali vapor flowing along those optical windows. Techniques disclosed herein may be implemented, for example, in a diode-pumped alkali laser (DPAL) system, in accordance with some embodiments.

Gaseous laser systems and related techniques are disclosed. Techniques disclosed herein may be utilized, in accordance with some embodiments, in providing a gaseous laser system with a configuration that provides (A) pump illumination with distinct edge surfaces for an extended depth and (B) an output beam illumination from a resonator cavity with distinct edges in its reflectivity profile, thereby providing (C) pump beam and output beam illumination on a volume so that the distinct edge surfaces of its pump and beam illumination are shared-edge surfaces with (D) further edge surfaces of the amplifier volume at the surfaces illuminated directly by the pump or output beams, as defined by optical windows and (optionally) by one or more flowing gas curtains depleted of the alkali vapor flowing along those optical windows. Techniques disclosed herein may be implemented, for example, in a diode-pumped alkali laser (DPAL) system, in accordance with some embodiments.

A narrow-band diode pumped alkali laser (DPAL) comprising a diode emitter assembly of broad area diode lasers arranged in a stack or array to emit longitudinally at a power level in a power range of 10-1500 W through a frequency selective element assembly aligned and positioned in an external laser cavity to the diode emitter assembly. The frequency selective element assembly comprising: an optical cell containing alkali vapor positioned between a pair of crossed polarizers; a partially reflective mirror that reflects a portion of light passing through the optical cell back toward the diode emitter assembly; and magnetic field producing components that produce a magnetic field through the optical cell that creates a 90 polarization of light passing through the optical cell at a narrow-band frequency corresponding to the absorption line of alkali atom, attenuating components of the light passing through the optical cell at frequencies outside of the narrow-band frequency.

Gaseous laser systems and related techniques are disclosed. Techniques disclosed herein may be utilized, in accordance with some embodiments, in providing a gaseous laser system with a configuration that provides (A) pump illumination with distinct edge surfaces for an extended depth and (B) an output beam illumination from a resonator cavity with distinct edges in its reflectivity profile, thereby providing (C) pump beam and resonator beam illumination on a volume so that the distinct edge surfaces of its pump and resonator beam illumination are shared-edge surfaces with (D) further edge surfaces of the amplifier volume at the surfaces illuminated directly by the pump or resonator beams, as defined by optical windows and (optionally) by one or more flowing gas curtains depleted of the alkali vapor flowing along those optical windows. Techniques disclosed herein may be implemented, for example, in a diode-pumped alkali laser (DPAL) system, in accordance with some embodiments.

An optically pumped, flowing gas, alkali metal laser includes a gas passageway transporting an alkali metal vapor and a hydrocarbon buffer gas, and a laser propagation passageway intersects the gas passageway and forms a main cell at the intersection. A pump laser is directed into the main cell and produces a main laser beam in the laser propagation passageway. The flowing hydrocarbon buffer gas is disposed in the main cell with a density to induce spin-orbit relaxation in the alkali metal vapor. At least one window is disposed in the laser propagation passageway, and the window is protected from deposits of alkali metal or carbon by a heated leading edge in the laser propagation passageway that re-vaporizes alkali metal and returns it to the gas passageway via a convective gas flow. The window is further protected by a cold block that liquefies alkali metal and by a colder block that solidifies alkali metal in the laser propagation passageway.

Gaseous laser systems and related techniques are disclosed. Techniques disclosed herein may be utilized, in accordance with some embodiments, in providing a gaseous laser system with a configuration that provides (A) pump illumination with distinct edge surfaces for an extended depth and (B) an output beam illumination from a resonator cavity with distinct edges in its reflectivity profile, thereby providing (C) pump beam and resonator beam illumination on a volume so that the distinct edge surfaces of its pump and resonator beam illumination are shared-edge surfaces with (D) further edge surfaces of the amplifier volume at the surfaces illuminated directly by the pump or resonator beams, as defined by optical windows and (optionally) by one or more flowing gas curtains depleted of the alkali vapor flowing along those optical windows. Techniques disclosed herein may be implemented, for example, in a diode-pumped alkali laser (DPAL) system, in accordance with some embodiments.

Techniques and architecture are disclosed for preserving optical surfaces (e.g., windows, coatings, etc.) in a flowing gas amplifier laser system, such as a diode-pumped alkali laser (DPAL) system. In some instances, the disclosed techniques/architecture can be used, for example, to protect optical surfaces in a DPAL system from: (1) chemical attack by pump-bleached alkali vapor atoms and/or ions; and/or (2) fouling by adherence thereto of reaction products/soot produced in the DPAL. Also, in some instances, the disclosed techniques/architecture can be used to substantially match the geometry of the pumping volume with that of the lasing volume, thereby minimizing or otherwise reducing the effects of amplified spontaneous emission (ASE) on DPAL output power. Furthermore, in some cases, the disclosed techniques/architecture can be used to provide a DPAL system capable of producing a beam output power in the range of about 20 kW to 10 MW, or greater.

Techniques and architecture are disclosed for managing alkali vapor concentration in a lasing gas at non-condensing levels. In some instances, the disclosed techniques/architecture can be used to control and/or stabilize the concentration of alkali vapor in a lasing gas volume to any desired fraction of its saturation value under dynamically changing thermal loads. In some such instances, the concentration of alkali vapor in a given lasing gas volume can be maintained at a value which is sufficiently far from the saturation point to prevent or otherwise reduce condensation of the alkali vapor, for example, upon accelerating the lasing gas through a pressure drop into an optical pumping cavity of an alkali vapor laser system (e.g., such as a diode-pumped alkali laser, or DPAL, system). In some instances, the disclosed techniques/architecture can be used to establish a temperature gradient and/or an alkali vapor concentration gradient in the flowing lasing gas volume.

Techniques and architecture are disclosed for preserving optical surfaces (e.g., windows, coatings, etc.) in a flowing gas amplifier laser system, such as a diode-pumped alkali laser (DPAL) system. In some instances, the disclosed techniques/architecture can be used, for example, to protect optical surfaces in a DPAL system from: (1) chemical attack by pump-bleached alkali vapor atoms and/or ions; and/or (2) fouling by adherence thereto of reaction products/soot produced in the DPAL. Also, in some instances, the disclosed techniques/architecture can be used to substantially match the geometry of the pumping volume with that of the lasing volume, thereby minimizing or otherwise reducing the effects of amplified spontaneous emission (ASE) on DPAL output power. Furthermore, in some cases, the disclosed techniques/architecture can be used to provide a DPAL system capable of producing a beam output power in the range of about 20 kW to 10 MW, or greater.