Abstract: A sensor head for use with a measurement grating is described. The sensor head comprises: a splitter grating configured to split a light beam into first and second measurement beams; a first retroreflector configured to retroreflect the first and second measurement beams toward the measurement grating; and a second retroreflector configured to retroreflect the first and second measurement beams toward the measurement grating. In one embodiment the second measurement beam is diffracted by the measurement grating to form first and second sub-beams and one of the first and second sub-beams comprises a zeroth order diffraction component and a first order diffraction component. In another embodiment, the first and second sub-beams each comprise a zeroth order diffraction component and a first order diffraction component.

Abstract: A sensor head for use with a measurement grating is described. The sensor head comprises: a splitter grating configured to split a light beam into first and second measurement beams; a first retroreflector configured to retroreflect the first and second measurement beams toward the measurement grating; and a second retroreflector configured to retroreflect the first and second measurement beams toward the measurement grating. In one embodiment the second measurement beam is diffracted by the measurement grating to form first and second sub-beams and one of the first and second sub-beams comprises a zeroth order diffraction component and a first order diffraction component. In another embodiment, the first and second sub-beams each comprise a zeroth order diffraction component and a first order diffraction component.

Abstract: A miniaturized optical beam recombiner combines beams from two optical fibers while maintaining the individual polarization mode.

Abstract: A light source system includes a beam source generating a first input beam of light. An anisotropic acousto-optic modulator (AOM) is positioned to receive the first input beam. The AOM includes a plurality of transducers for receiving control signals and generating corresponding acoustic waves that operate on the first input beam to generate first and second output beams with different frequencies and orthogonal linear polarizations. The first and second output beams have a combined optical power that is substantially the same as an optical power of the first input beam for a first input beam with one polarization and for a first input beam with two polarizations.

Abstract: A light source system includes a beam source generating a first input beam of light with first and second beam components. The first component has a first linear polarization and a first frequency. The second component has a second linear polarization and a second frequency. The first and second linear polarizations are orthogonal. An anisotropic acousto-optic modulator (AOM) is positioned to receive the first input beam. The AOM is operable to change the polarization and frequency of the first and the second beam components in response to a control signal, and thereby generate first and second output beams corresponding to the first and second components, respectively.

Abstract: A manipulator for a fiber optic cable assembly (FOCA) provides microradian accuracy in control of the direction of a beam emanating from the FOCA. Such manipulators can control FOCAs to control the incidence angles of beams at a beam combiner in a beam-combining unit. Accordingly, fewer additional optical elements are required for control of input paths in the beam-combining unit. The manipulator and the beam-combining unit are accurate enough for use in an interferometer that combines beams with different frequencies and polarizations. One such interferometer includes a Zeeman split laser providing a heterodyne beam. A beam splitter separates frequency components of the beams, and AOMs increase the frequency separation between the separated beams. The separated beams can be sent via optical fibers to the beam-combining unit, which combines the beams for use in interferometer optics.

Abstract: A method of digitizing first and second signals in imperfect quadrature for obtaining characteristic parameters of the first signal comprises providing a first signal, the first signal comprising an inphase quasi-sinusoidal analog signal. The method comprises providing a second signal, the second signal comprising a quadrature signal. The method comprises digitizing the first signal at a sampling rate, thereby generating a first plurality of sets of digital signal waveform samples and digitizing the second signal at the sampling rate, thereby generating a second plurality of sets of digital signal waveform samples. The method comprises digitally processing successive first and second sets of digital signal waveform samples to generate continually updated digital characteristic parameters representing a characteristic behavior of the first signal.

Abstract: A manipulator for a fiber optic cable assembly (FOCA) provides microradian accuracy in control of the direction of a beam emanating from the FOCA. Such manipulators can control FOCAs to control the incidence angles of beams at a beam combiner in a beam-combining unit. Accordingly, fewer additional optical elements are required for control of input paths in the beam-combining unit. The manipulator and the beam-combining unit are accurate enough for use in an interferometer that combines beams with different frequencies and polarizations. One such interferometer includes a Zeeman split laser providing a heterodyne beam. A beam splitter separates frequency components of the beams, and AOMs increase the frequency separation between the separated beams. The separated beams can be sent via optical fibers to the beam-combining unit, which combines the beams for use in interferometer optics.