Methods and systems are provided for separating polarized UV light. In one example, a method may include passing polarized source light through a group of at least four prisms to collimate and separate a second-harmonic generation (SHG) beam from a pump beam. The separated SHG beam may then be further passed through a spatial filter to reduce spatial distribution.

Methods and systems are provided for separating polarized UV light. In one example, a method may include passing polarized source light through a group of at least four prisms to collimate and separate a second-harmonic generation (SHG) beam from a pump beam. The separated SHG beam may then be further passed through a spatial filter to reduce spatial distribution.

The present invention describes a laser system for eliminating astigmatism to produce an elliptical laser beam that has an ellipticity between about 0.9 to 1.0. The laser system described herein allows for increased conversion efficiency and output powers. on-linear optical elements in the laser system eliminate astigmatism. The laser system comprises one or more cavities with wavelength splitters that act as dual-minor chambers for single-pass light transmission through the non-linear optical elements to reduce cavity size or as beam splitters for double-pass light transmission through the non-linear optical elements to increase laser output power. The laser system may also include a birefringent filter and/or etalon in the first cavity for polarization and wavelength tuning. The laser system may also generate a high-power, deep-ultraviolet laser output. The laser system may also be devoid of curved mirrors and non-normal incidence reflection to eliminate astigmatism.

The present invention describes a laser system for eliminating astigmatism to produce an elliptical laser beam that has an ellipticity between about 0.9 to 1.0. The laser system described herein allows for increased conversion efficiency and output powers. on-linear optical elements in the laser system eliminate astigmatism. The laser system comprises one or more cavities with wavelength splitters that act as dual-minor chambers for single-pass light transmission through the non-linear optical elements to reduce cavity size or as beam splitters for double-pass light transmission through the non-linear optical elements to increase laser output power. The laser system may also include a birefringent filter and/or etalon in the first cavity for polarization and wavelength tuning. The laser system may also generate a high-power, deep-ultraviolet laser output. The laser system may also be devoid of curved mirrors and non-normal incidence reflection to eliminate astigmatism.

A crystal quartz element includes a main face provided with a plurality of polarity inverted regions and a polarity non-inverted region, the plurality of polarity inverted regions are spaced apart from each other via the polarity non-inverted region, and the main face is a plane face. A method for manufacturing a crystal quartz element includes: preparing a crystal quartz body including a first main face which is a plane face, and a first pressing jig including a first pressing face on which a plurality of first projections are provided; and forming a plurality of polarity inverted regions corresponding to the plurality of first projections in the crystal quartz body by heating and pressing the first main face by the first pressing face.

A system and methods for ghost imaging second harmonic generation microscopy. Imaging data is collected in parallel, providing faster imagine reconstruction and enabling reconstruction in scattering environments. Ghost imaging, split light beam interacting with a target and a second light beam unimpeded and not required to pass through the same background. A second harmonic generation image is reconstructed from the detected photons.

A system and methods for ghost imaging second harmonic generation microscopy. Imaging data is collected in parallel, providing faster imagine reconstruction and enabling reconstruction in scattering environments. Ghost imaging, split light beam interacting with a target and a second light beam unimpeded and not required to pass through the same background. A second harmonic generation image is reconstructed from the detected photons.

A frequency conversion laser system is configured with a single mode (SM) laser source outputting a pulsed pump beam at a fundamental frequency and a nonlinear optical system operating to convert the fundamental frequency sequentially to a second harmonic (SH) and then third harmonic (TH). The nonlinear optical system includes an elongated SHG crystal traversed by the SM pulsed pump beam which generates the SH beam. The SHG crystal has an output surface inclined relative to a longitudinal axis of the SHG crystal at a first wedge angle different from a right angle. The nonlinear optical system further has an elongated THG crystal with an input surface which is impinged upon by a remainder of the pump and SHG beams which propagate through the THG crystal at a walk-off angle therebetween to generate a third harmonic (TH) beam, the input surface of the THG crystal being inclined to a longitudinal axis of the THG crystal at a second wedge angle. The output and input surfaces of respective SHG and THG crystals are inclined so as to minimize the walk-off angle between SH and IR pointing vectors in the THG crystal thereby improving the conversion efficiency and TH output beam's ellipticity.

A frequency conversion laser system is configured with a single mode (SM) laser source outputting a pulsed pump beam at a fundamental frequency and a nonlinear optical system operating to convert the fundamental frequency sequentially to a second harmonic (SH) and then third harmonic (TH). The nonlinear optical system includes an elongated SHG crystal traversed by the SM pulsed pump beam which generates the SH beam. The SHG crystal has an output surface inclined relative to a longitudinal axis of the SHG crystal at a first wedge angle different from a right angle. The nonlinear optical system further has an elongated THG crystal with an input surface which is impinged upon by a remainder of the pump and SHG beams which propagate through the THG crystal at a walk-off angle therebetween to generate a third harmonic (TH) beam, the input surface of the THG crystal being inclined to a longitudinal axis of the THG crystal at a second wedge angle. The output and input surfaces of respective SHG and THG crystals are inclined so as to minimize the walk-off angle between SH and IR pointing vectors in the THG crystal thereby improving the conversion efficiency and TH output beam's ellipticity.

In one aspect, a device is disclosed that includes one or more input ports structured to receive a pumping light at a pumping wavelength and a signal light at a signal wavelength, and one or more output ports structured to output light including an amplified signal light at the signal wavelength and a second harmonic idler light. The device includes a nonlinear optical material to mix the pumping light and the signal light and to cause nonlinear conversion of the pumping light into the amplified signal light and generate an idler light at an idler wavelength. The nonlinear optical material is further structured to convert the idler light into the second harmonic idler light which eliminates the idler light at the one or more output ports and prevents back-conversion of the amplified signal light and idler light to the pumping wavelength.