Optical modulator

About: Optical modulator is a research topic. Over the lifetime, 14068 publications have been published within this topic receiving 196932 citations.

Waveguide-Type Optical Modulator of GaAs Quantum Well Double Heterostructures Using Electric Field Effect on Exciton Absorption

Abstract: This letter describes a GaAs/AlGaAs quantum well (QW) waveguide-type optical modulator utilizing an electric field effect on two-dimensional exciton absorption. The waveguide modulator has the same structure as QW laser diodes, and is therefore suitable for monolithic integration with a laser diode. Optical modulation was measured up to 1 Gbit/s at a driving voltage as low as 1.4 V. The 3 dB-down modulation rate was 900 Mbit/s, but higher speed operation is expected.

Electronically tuneable light source

Abstract: An electronically tuneable light source includes a source (10) of white light, an acousto-optic modulator (16) which includes a transparent medium and means (17) for generating an acoustical wave in the medium, and means for directing the collimated beam of the white light onto the medium at a preselected angle θ/2 to a line which is perpendicular to the direction of travel of the acoustical wave. Interaction of the light beam with the acoustical wave causes diffraction of the light beam. Means (22) are provided for selecting a visible band of the diffracted beam at an angle to the incident collimated beam of light equal to approximately 8.

Integrated optical modulator

Abstract: Systems and methods for manipulating light with high index contrast waveguides clad with crystalline substances having that exhibit large nonlinear electro-optic constants χ 2 and χ 3 . Waveguides fabricated on SOI wafers and clad with crystalline materials such as barium titanate are described. Embodiments of waveguides having slots, electrical contacts, and input waveguide couplers are discussed. Waveguides having closed loop structures (such as rings and ovals) as well as linear or serpentine waveguides, are described. Optical signal processing methods, such as optical rectification and optical modulation, are disclosed.

Photorefractive p-i-n diode quantum well spatial light modulators

Abstract: We demonstrate the performance of all‐semiconductor photorefractive p‐i‐n diodes operating in the longitudinal quantum‐confined Stark geometry. Low‐temperature‐grown shallow quantum wells provide high‐mobility vertical transport, and potential steps incorporated into the semiconductor buffer layers increase the transit time across the buffer and therefore increase the quantum efficiency for trapping of charge before it is swept out to the doped p‐type and n‐type contacts. The buffer design and the doped contacts both make all‐semiconductor photorefractive devices possible, with peak transient output diffraction efficiencies approaching 3%, but without the need for dielectric insulating layers. We also redefine device speed by making a distinction between transient rise times and frequency response, showing that in these p‐i‐n devices the update rate is an order of magnitude slower than the inverse rise time.

Microfabricated continuous cubic phase plate induced Airy beams for optical manipulation with high power efficiency

Abstract: We studied and demonstrated optical trapping capabilities of an Airy beam generated with a cubic phase plate incorporated into a conventional optical tweezer system. The power efficiency and damage threshold of the cubic phase plate were found to be much higher when spatial light modulators were employed in beam generation.