A laser pumping method pumps a primary amount of energy into a laser medium to populate an intermediate level near an upper laser level. A lesser amount of energy is pumped into the laser medium to populate an excited level that lies above the upper laser level and transfers atomic or molecular population to the upper laser level by a nonradiative process. A laser device includes a laser medium supporting four levels, including a lower laser level, an upper laser level, an excited level above the laser level from which population transfers to the upper laser level via nonradiative transition, and an intermediate level within a few kT of the upper laser level.

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 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.

A laser pumping method pumps a primary amount of energy into a laser medium to populate an intermediate level near an upper laser level. A lesser amount of energy is pumped into the laser medium to populate an excited level that lies above the upper laser level and transfers atomic or molecular population to the upper laser level by a nonradiative process. A laser device includes a laser medium supporting four levels, including a lower laser level, an upper laser level, an excited level above the laser level from which population transfers to the upper laser level via nonradiative transition, and an intermediate level within a few kT of the upper laser level.

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 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.

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.

A laser system including a laser cavity, a gain medium disposed in the laser cavity, a pump configured to excite an atom of the gain medium to an excited state, an optical device configured to couple a ground state of the atom of the gain medium to the excited state by applying an optical field to the gain medium, and a microwave device configured to couple the ground state of the atom of the gain medium to a different ground state by applying a microwave field to the gain medium.

A laser system including a laser cavity, a gain medium disposed in the laser cavity, a pump configured to excite an atom of the gain medium to an excited state, an optical device configured to couple a ground state of the atom of the gain medium to the excited state by applying an optical field to the gain medium, and a microwave device configured to couple the ground state of the atom of the gain medium to a different ground state by applying a microwave field to the gain medium.