A device and method for phase imaging and element detection based on wavefront modulation are provided to overcome the disadvantages of an existing interferometry such as twin image elimination, limit resolution, under-sampling wavefront measurement, and multi-modal measurement. From the perspective of light field encoding, the accurate measurement to a complex amplitude of a light field to be measured is completely achieved by the iterative calculation, and at the same time, a twin image problem may be effectively eliminated, and it has the multi-modal (multi-wavelength) reconstruction ability. Theoretically, it is able to reach the diffraction limit resolution, may be widely used in phase imaging, optical element surface-type detection, polarization distribution measurement and the like, and it has a wide range of applications.

A phase modulation structure includes a recording surface including phase angle recording regions in a plurality of calculated element regions corresponding to reconstruction points of an image on a one-to-one basis, each phase angle recording region being formed of a plurality of unit blocks in each of which a phase angle is recorded, the phase angle being calculated based on a phase that is a sum of a plurality of phases of light from the corresponding reconstruction points; and a representative area that is one of divisions of the calculated element region, the representative area being obtained by radially dividing the calculated element region centered on a point on the calculated element region, the point being obtained by extending a normal line from the corresponding reconstruction point to the calculated element region on the recording surface.

Conformal imaging vibrometer using adaptive optics with scene-based wave front sensing. An extended object is located at the first end of a link, and a reference-free, adaptive optical, conformal imaging vibrometer using scene-based wave front sensing is located at the second end of the link. An aberrated, free space or guided-wave path exists between the ends of the link. The adaptive optical system compensates for path distortions. Using a single interrogation beam, whole-body vibrations of opaque and reflective objects can be probed, as well as transparent and translucent objects, the latter pair employing a Zernike heterodyne interferometer.

An optical spectrum analyzer (OSA) for measuring an optical spectrum of an input optical signal in a measurement wavelength range is provided. The OSA comprises a modulator, an integrated optical filter, and a photodetector. The modulator modulates the input optical signal by applying a dither modulation to facilitate detection and noise rejection. The integrated optical filter, which may include a ring resonator system, is sequentially tunable to selectively transmit each wavelength of the modulated optical signal in the measurement wavelength range. The photodetector sequentially detects each wavelength of the modulated optical signal in the measurement wavelength range to provide a representative output electrical signal.

A laser detection system and method of two way communication comprising: a Mach Zehnder interferometer, the Mach Zehnder interferometer comprising: an entry beam splitter for splitting incident light into a first arm, having an arm length L1 and a second arm having an arm length L2; a modulation stage for receiving a modulation signal and applying a phase difference to the second arm, the magnitude of the phase difference depending upon the magnitude of the modulation signal; an exit beam splitter for recombining light from the first arm with light from the second arm to create a first output and a second output; a detection stage comprising a first detector at the first output for detecting intensity modulation caused by interference of the recombined light; and a signal processor communicably connected to both the modulation stage and the detection stage.

A laser detection system and method of two way communication comprising: a Mach Zehnder interferometer, the Mach Zehnder interferometer comprising: an entry beam splitter for splitting incident light into a first arm, having an arm length L1 and a second arm having an arm length L2; a modulation stage for receiving a modulation signal and applying a phase difference to the second arm, the magnitude of the phase difference depending upon the magnitude of the modulation signal; an exit beam splitter for recombining light from the first arm with light from the second arm to create a first output and a second output; a detection stage comprising a first detector at the first output for detecting intensity modulation caused by interference of the recombined light; and a signal processor communicably connected to both the modulation stage and the detection stage.

A phase modulation structure includes a recording surface including phase angle recording regions in a plurality of calculated element regions corresponding to reconstruction points of an image on a one-to-one basis, each phase angle recording region being formed of a plurality of unit blocks in each of which a phase angle is recorded, the phase angle being calculated based on a phase that is a sum of a plurality of phases of light from the corresponding reconstruction points; and a representative area that is one of divisions of the calculated element region, the representative area being obtained by radially dividing the calculated element region centered on a point on the calculated element region, the point being obtained by extending a normal line from the corresponding reconstruction point to the calculated element region on the recording surface.

In order to measure the contrast of interference in an interference-based, closed-loop, phase-modulating optical sensor device, the gain of the feedback loop in a feedback controller is evaluated. This gain is found to be a measure for the contrast. The contrast evaluated in this way can e.g. be used for period-disambiguation when determining the measurand of the sensor device. The sensor device can e.g. be a high-voltage sensor or a current sensor.

A system includes a source of laser beams forming an array, a source of a reference laser beam, and an optical detector for measuring respective phase differences between the array laser beams and the reference laser beam. The system includes a mask, having apertures with a shape, size and position identical to a shape, size and position of the array laser beams, and positioned in the reference laser beam to form respective beams of the reference laser beam corresponding to the beams from the array laser beams. A phase modulator phase modulates respective beams of one of (a) the array laser beams and (b) the beams of the reference laser from the mask. A photodetector receives the respective array laser beams and the corresponding reference laser beams from the mask to generate a composite signal. Processing circuitry is responsive to the composite signal for generating respective signals representing the phase differences of the individual laser beams from the reference laser beam.

In order to measure the contrast of interference in an interference-based, closed-loop, phase-modulating optical sensor device, the gain of the feedback loop in a feedback controller (12) is evaluated. This gain is found to be a measure for the contrast. The contrast evaluated in this way can e.g. be used for period-disambiguation when determining the measurand of the sensor device. The sensor device can e.g. be a high-voltage sensor or a current sensor.