Abstract: An infrared wave front phase analyzer that can be used for measuring the wave front phase of laser diode (LD) beam to provide a quality characterization specification for the LD chips that are intended for use in optical sub-assemblies (OSAs), which has applications in optical transceiver manufacturing and fiber optic communications. An optical system mimics the OSA and includes optical elements to collect and collimate the LD output beam and to focus the collimated beam through a focus, which could otherwise be into the end of an optical fiber, before re-collimating the laser beam for evaluation by a wave front sensor. This imaging process measures a wave front of the output beam, yielding a quality specification of the LD for screening out the out-of-spec LDs in advance of their assembly within TOSA/BOSA manufacturing to lower production costs.

Abstract: A differential curvature sensing device for measuring a wavefront curvature by employing increased spatial sampling for wavefront testing with mid-frequency error recovery. The device includes a sampling sensor having an output beam, an optical element to split said output beam, a lenslet array in the path of each beam to generate corresponding sampling grids, a shearing element for shifting the grid points in horizontal and vertical directions to produce plural sampling grids having plural grid points for use generating a spatial sampling grid having a density for mid-spatial frequency recovery. The displacement of the shifting less than a pitch size of the lenslet array, and a measuring device measuring plural slopes of plural wavefronts at each grid point to obtain a wavefront normal curvature and corresponding twist curvature terms to determine a principal curvature and directions. The sensor is a Shack-Hartman sensor, shearing interferometer sensor and other discrete-point sampling sensors.

Abstract: A differential Shack-Hartmann curvature sensor for measuring a curvature including principal curvatures and directions of a wavefront. The curvature sensor includes a Shack-Hartmann sensor with an input beam and an optical element to split said input beam into three output beams traveling in different directions. Three lenslet arrays in each of the three beam paths produce corresponding Hartmann grids. A shearing device shears two of the three Hartmann grids in two perpendicular directions a differential difference. A measuring device measures the Hartmann grid coordinates generated by said three beams to determine various curvatures of the wavefront at each of the Hartmann grid points.

Abstract: A differential Shack-Hartmann curvature sensor for measuring a curvature including principal curvatures and directions of a wavefront. The curvature sensor includes a Shack-Hartmann sensor with an input beam and an optical element to split said input beam into three output beams traveling in different directions. Three lenslet arrays in each of the three beam paths produce corresponding Hartmann grids. A shearing device shears two of the three Hartmann grids in two perpendicular directions a differential difference. A measuring device measures the Hartmann grid coordinates generated by said three beams to determine various curvatures of the wavefront at each of the Hartmann grid points.

Abstract: Iterative algorithm methods and systems for slope or gradient-type data is presented for wavefront zonal estimation of regular and irregular pupil shapes. The methods and systems bears universal wavefront estimation matrices that are directly applicable to any pupil shape without the need to set up new matrices. The algorithm consists in first extending the sampling pupil to a larger regular square shape and second extrapolating the sampled slope data outside of the sampling pupil employing Gerchberg-type iterations. Unbiased least-squares wavefront estimation is then performed in the square domain. Results show that the RMS deviation error of the estimated wavefront from the original wavefront can be less than ?/150 after about twelve iterations and less than ?/100 (both for ? equal 632.8 nm) within as few as five iterations.