Abstract: A fiber laser device includes a laser source that can emit a source laser beam, a birefringent beam separator configured to receive the source laser beam and to split the source laser beam into an o ray and an e ray which have mutually orthogonal polarizations, and a polarization maintaining fiber comprising a fiber core characterized by a core diameter, wherein after the o ray and the e ray exit birefringent beam separator, the o ray and the e ray are separated by a distance that is larger than the fiber core of the polarization maintaining fiber. The polarization maintaining fiber is positioned to couple one of the o ray and the e ray into the fiber core. The one of the o ray and the e ray transmits through the polarization maintaining fiber to form an output laser beam.

Abstract: A method for making a microchip laser includes preparing a laser-cavity chip assembly comprising a gain media, a first substantially flat surface, and a second substantially flat surface parallel to the first substantially flat surface. The method also includes forming a first reflective film on the first substantially flat surface to form a first cavity mirror, forming a second reflective film on the second substantially flat surface to form a second cavity mirror, and patterning at least one of the first reflective film or the second reflective film by removing at least a portion of the reflective film in the outer portion to form a center reflective portion in the one of the first reflective film or the second reflective film. The first cavity mirror and the second cavity mirror can suppress higher order transverse modes and produce a single TEM00 mode in the lasing light.

Abstract: An integrated optical-amplification module includes a housing member, a first input optical terminal configured to receive an optical signal, a second input, optical terminal that can receive a pump light, and an output optical terminal that can output a combined optical signal comprising at least a portion of the optical signal and a portion of the pump light. The integrated optical-amplification module also includes an optical combiner fixedly installed relative to the housing member. The optical combiner can receive the pump light and the optical signal and an optical prism fixedly installed relative to the housing member. The optical combiner can merge the pump light and the optical signal to form the combined optical signal. The optical prism can direct at least a portion of the optical signal through free space to the optical combiner.

Abstract: An optical isolator includes a birefringent material and a Faraday rotator. The birefringent material receives a forward light propagating in a forward direction and a backward light propagating opposite to the forward direction. The birefringent material has an optical axis, wherein the forward light has a first polarization aligned perpendicular to the optical axis and is configured to pass the first birefringent material substantially along the forward direction. At least a portion of the backward light has a second polarization not perpendicular to the optical axis. The first birefringent material can displace the backward light to form a first displaced backward light. A Faraday rotator can rotate the forward light, and the backward light or the first displaced backward light by a same predetermined angle along the rotation direction.

Abstract: A low-noise micro-chip laser includes a diode pump, a gain medium, a nonlinear crystal, and a birefringent material. The gain medium can receive the energy from the diode pump and generate a laser beam at a fundamental wavelength. The nonlinear crystal can generate a frequency-doubled laser beam in response to the laser beam at the fundamental wavelength. To reduce noise in the frequency-doubled laser beam, the birefringent material and the nonlinear crystal in combination are designed to function as a quarter wave plate at the fundamental wavelength.