Birefringence-free photoelastic modulator with centimeter-square aperture operating at 2.7 MHz with sub-watt drive power.

Photoelastic modulators are optical devices with a broad range of applications. These devices typically utilize a transverse interaction mechanism between acoustic and optical waves, resulting in a fundamental trade-off between the input aperture and the modulation frequency. Commercially available modulators with centimeter-square apertures have operating frequencies in the vicinity of 50 kHz.

Polarization-insensitive wide-angle resonant acousto-optic phase modulator.

Phase modulators are commonly used devices in optics. Free-space phase modulators are typically constructed from optically anisotropic crystals exhibiting the Pockels effect. To preserve the light's polarization state as it propagates through the crystal, it is essential to align the polarization and the angle of incidence of the light with respect to the crystal.

Optically isotropic longitudinal piezoelectric resonant photoelastic modulator for wide angle polarization modulation at megahertz frequencies.

Polarization modulators have a broad range of applications in optics. The acceptance angle of a free-space polarization modulator is crucial for many applications. Polarization modulators that can achieve a wide acceptance angle are constructed by attaching a piezoelectric transducer to an isotropic material, and utilizing a resonant transverse interaction between light and acoustic waves.

Y-Z cut lithium niobate longitudinal piezoelectric resonant photoelastic modulator.

The capability to modulate the intensity of an optical beam has scientific and practical significance. In this work, we demonstrate Y-Z cut lithium niobate acousto-optic modulators with record-high modulation efficiency, requiring only 1.5 W/cm for 100% modulation at 7 MHz.

Longitudinal piezoelectric resonant photoelastic modulator for efficient intensity modulation at megahertz frequencies.

Intensity modulators are an essential component in optics for controlling free-space beams. Many applications require the intensity of a free-space beam to be modulated at a single frequency, including wide-field lock-in detection for sensitive measurements, mode-locking in lasers, and phase-shift time-of-flight imaging (LiDAR). Here, we report a new type of single frequency intensity modulator that we refer to as a longitudinal piezoelectric resonant photoelastic modulator.

Spectrally sparse optical coherence tomography.

Swept-source optical coherence tomography (OCT) typically relies on expensive and complex swept-source lasers, the cost of which currently limits the suitability of OCT for new applications. In this work, we demonstrate spectrally sparse OCT utilizing randomly spaced low-bandwidth optical chirps, suitable for low-cost implementation with telecommunications grade devices. Micron scale distance estimation accuracy with a resolution of 40 μm at a standoff imaging distance greater than 10 cm is demonstrated using a stepped chirp approach with approximately 23% occupancy of 4 THz bandwidth.

Time-of-flight imaging based on resonant photoelastic modulation: publisher's note.

This publisher's note corrects the Funding section in Appl. Opt.58, 2235 (2019)APOPAI0003-693510.

Time-of-flight imaging based on resonant photoelastic modulation.

A time-of-flight imaging system is proposed and its working principle demonstrated. To realize this system, a new device, a free-space optical mixer, is designed and fabricated. A scene is illuminated (flashed) with a megahertz-level amplitude-modulated light source, and the reflected light from the scene is collected by a receiver.