Abstract: Apparatus and methods of controlling a frequency-converted diode laser system are disclosed. The diode laser systems can include embodiments of thermally coupled elements facilitating temperature stabilization. Aspects of some methods include monitoring the output of a stabilized diode laser system to reduce noise of the output laser beam. Other aspects of some methods include adjusting the temperature of a frequency converter based on noise in the output beam, and/or the current provided to drive the diode laser. Systems incorporating such control aspects, and others, are also disclosed.

Abstract: Apparatus and methods of controlling a frequency-converted diode laser system are disclosed. The diode laser systems can include embodiments of thermally coupled elements facilitating temperature stabilization. Aspects of some methods include monitoring the output of a stabilized diode laser system to reduce noise of the output laser beam. Other aspects of some methods include adjusting the temperature of a frequency converter based on noise in the output beam, and/or the current provided to drive the diode laser. Systems incorporating such control aspects, and others, are also disclosed.

Abstract: Apparatus and methods of controlling a frequency-converted diode laser system are disclosed. The diode laser systems can include embodiments of thermally coupled elements facilitating temperature stabilization. Aspects of some methods include monitoring the output of a stabilized diode laser system to reduce noise of the output laser beam. Other aspects of some methods include adjusting the temperature of a frequency converter based on noise in the output beam, and/or the current provided to drive the diode laser. Systems incorporating such control aspects, and others, are also disclosed.

Abstract: Apparatus and methods are disclosed for transforming a laser beam to a polarized shaped beam in, for example, a frequency converted laser system. In one embodiment, an anamorphic optical system includes a first prism and a second prism that can be configured to form a Brewster telescope, the first prism and second prism each having an input surface and an exit surface, and wherein at least one surface of the input or exit surfaces are coated with a polarization selective coating. The optical system can include an adjustment system configured to change the position of one or both of the first prism and the second prism to adjust the transformation of the shape of the laser beam. In some embodiments of the optical system, a configuration of the first prism, the second prism, and the polarization selective coating produce a laser beam having a polarization ratio of about 100:1 or higher.

Abstract: Apparatus and methods are disclosed for transforming a laser beam to a polarized shaped beam in, for example, a frequency converted laser system. In one embodiment, an anamorphic optical system includes a first prism and a second prism that can be configured to form a Brewster telescope, the first prism and second prism each having an input surface and an exit surface, and wherein at least one surface of the input or exit surfaces are coated with a polarization selective coating. The optical system can include an adjustment system configured to change the position of one or both of the first prism and the second prism to adjust the transformation of the shape of the laser beam. In some embodiments of the optical system, a configuration of the first prism, the second prism, and the polarization selective coating produce a laser beam having a polarization ratio of about 100:1 or higher.

Abstract: An optical illuminator assembly (10) for locating an object (20) in inclement conditions (22) includes a MIR laser source (12) having a semiconductor laser that directly emits (without frequency conversion) an output beam (16) that is in the MIR range, the output beam (16) being useful for locating the object (20). Additionally, the optical illuminator assembly (10) can include a MIR imager (14) that captures an image (18) of light in the MIR range near the object (20). Further, the MIR imager (14) can include an image display (26) that displays the captured image (18). In a first example, the MIR laser source (12) and the MIR imager (14) are spaced apart, and the image (18) captured by the MIR imager (14) includes the output beam (16) from the MIR laser source (12). With this design, a person (28) operating a vehicle (24) will be able to locate the object 20 in inclement conditions 22. In a second example, the MIR laser source (12) and the MIR imager (14) are positioned in close proximity to each other.

Abstract: Apparatus and methods are disclosed for transforming a laser beam to a polarized shaped beam in, for example, a frequency converted laser system. In one embodiment, an anamorphic optical system includes a first prism and a second prism that can be configured to form a Brewster telescope, the first prism and second prism each having an input surface and an exit surface, and wherein at least one surface of the input or exit surfaces are coated with a polarization selective coating. The optical system can include an adjustment system configured to change the position of one or both of the first prism and the second prism to adjust the transformation of the shape of the laser beam. In some embodiments of the optical system, a configuration of the first prism, the second prism, and the polarization selective coating produce a laser beam having a polarization ratio of about 100:1 or higher.

Abstract: An imaging system (10) for imaging an emitting gas (12) includes an imager (16) and a laser source (20). The imager (16) captures an image (18) of light in the mid-infrared (MIR) range. The laser source (20) includes a semiconductor laser (334) that directly emits an output beam (26) that is in the MIR range. The output beam (26) may be adapted to backscatter near and/or be absorbed by the emitting gas (12). Thus, when an emitting gas (12) is present, the gas (12) may absorb and attenuate the backscattered light. As a result thereof, a shadow or contrast (18A) corresponding to the emitting gas (12) may be visible in the image (18) that is captured by the imager (16).

Abstract: A diode-pumped solid-state laser including a short wavelength (e.g., blue, violet, or UV) semiconductor laser that pumps an absorption transition in a rare-earth-doped material. Responsive to this pumping, the rare-earth active ion directly emits laser radiation. A number of different wavelength outputs, including short wavelengths, are achievable dependent upon the material and the pump wavelength. The gain medium may include an active ion selected from Er3+ Sm3+, Eu3+, Tb3+, Dy3+, Tm3+, Ho3+, and Pr3+. A laser diode pump source has a wavelength in the range of about 365 nm to 480 nm to excite a laser emission in the range of 370 to 800 nm. The laser diode pump source may comprise a GaN-based semiconductor. In some embodiments, the laser diode pump source supplies a pump beam in a range of 370–380 nm, 400–415 nm, 435–445 nm, or 468–478 nm.

Abstract: A single frequency filter for a laser, comprising a polarizer that defines a direction of polarization and one or more birefringent elements situated within the cavity with their dielectric axes offset from the direction of polarization. The ends of the birefringent elements have a finite reflectance, and may be coated for reflectance or left uncoated. In some embodiments the filter is situated in a laser cavity with a broadband gain medium, in other embodiments, the filter is situated in an external cavity. To provide tunability, a wavelength control system is coupled to the birefringent element. An embodiment is described in which the filter comprises two birefringent elements of unequal optical length along the optical axis, which advantageously reduces the voltage required to tune the frequency. To provide tunability, the first and second birefringent elements are both coupled to a wavelength control system that simultaneously controls both elements.

Abstract: A single frequency filter for a laser, comprising a polarizer that defines a direction of polarization and one or more birefringent elements situated within the cavity with their dielectric axes offset from the direction of polarization. The ends of the birefringent elements have a finite reflectance, and may be coated for reflectance or left uncoated. In some embodiments the filter is situated in a laser cavity with a broadband gain medium, in other embodiments, the filter is situated in an external cavity. To provide tunability, a wavelength control system is coupled to the birefringent element. An embodiment is described in which the filter comprises two birefringent elements of unequal optical length along the optical axis, which advantageously reduces the voltage required to tune the frequency. To provide tunability, the first and second birefringent elements are both coupled to a wavelength control system that simultaneously controls both elements.

Abstract: A laser in which the laser emission is autocoupled into an optical fiber. The laser cavity is insensitive to misalignment; i.e. it will oscillate if the optical fiber is positioned within an allowed volume determined by a degenerate resonator configuration. In one embodiment, a solid state laser includes two ball lenses arranged on opposing sides of the gain medium. The degenerate resonator configuration is defined on one end by a reflectively-coated outer surface of the ball lens. The other end is approximately defined by an allowed volume on the outer surface of the second ball lens. To provide a laser cavity the reflective end of the optical fiber is situated within the allowed volume. The laser may be end-pumped using a fiber-coupled laser diode, and the ball lens is used to focus the pump beam into the gain medium. The reflective end may be provided by a Bragg grating.