Optical modulator

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

Optical modulator including graphene

Abstract: An optical modulator includes a first graphene and a second graphene on an upper surface of a semiconductor layer, a first electrode on the first graphene, and a second electrode on the second graphene. Respective side surfaces of the first graphene and the second graphene are separated from each other. A first ridge portion of the semiconductor layer and a second ridge portion on the second graphene constitute an optical waveguide, and the first and second graphenes are on a center portion of the optical waveguide in a vertical direction to the semiconductor.

Analysis and design of high-speed high-efficiency GaAs-AlGaAs double-heterostructure waveguide phase modulator

Abstract: A P-p-i-n-N, GaAs-AlGaAs, TE/TM mode phase modulator, which has both the high phase shift efficiency of a p-n homojunction modulator and the high speed associated with a P-i-N modulator, is considered by incorporating p- and n-GaAs buffer layers and utilizing the higher order effects in these layers The device structure is analyzed by considering the individual contributions of both the electrooptic (linear electrooptic (LEO) and quadratic electrooptic (QEO)) effects and the free carrier (plasma (PL) and bandgap shift (BS)) effects These effects are studied in detail as a function of the reverse bias, operating wavelength, doping concentration, and intrinsic layer thickness The results are in excellent agreement with the theoretical predictions >

System for the display of images given by a spatial modulator with transfer of energy

Abstract: A system for the display of images comprising: a spatial modulator of light receiving a first light beam and retransmitting a modulated beam; an energy transfer device receiving the modulated beam and a second light beam and transferring the energy from the second light beam towards the modulated beam.

Light modulation device for a display for representing two- and/or three-dimensional image content

Abstract: The invention relates to a light modulation device for a display for representing two- and/or three-dimensional image content or image sequences. The light modulation device comprises a light modulator and a controller. The phase and/or the amplitude of a light wave field, which is substantially collimated, can be varied by means of the light modulator depending on the location of the light modulator. The light modulator can be actuated by means of the control device. According to the invention, in the direction of propagation of the light wave field, at least one diffracting unit is arranged downstream of the light modulator. The diffracting unit has a variable diffracting structure. By means of the diffracting structure, the light wave field varied by the light modulator can be diffracted in a variable and predeterminable manner. Further, the present invention relates to a display and a method for producing a light modulation device.

First Demonstration of Athermal Silicon Optical Interposers With Quantum Dot Lasers Operating up to 125 °C

Abstract: We previously proposed a photonics-electronics convergence system to solve bandwidth bottleneck problems among large-scale integrations (LSIs) and demonstrated a high bandwidth density with silicon optical interposers at room temperature. For practical applications, the interposers should be usable under high-temperature conditions or rapid temperature changes so that they can cope with the heat generated by the mounted LSIs. We designed and fabricated athermal silicon optical interposers integrated with temperature-insensitive components on a silicon substrate. An arrayed laser diode (LD) chip was a flip-chip bonded to the substrate. Each LD had multiple quantum dot layers with a 1.3-μm lasing wavelength. The output power was higher than 10 mW per channel up to 100 °C. Silicon optical modulator and germanium photodetector (PD) arrays were monolithically integrated on the substrate. The modulators were structured as symmetric Mach–Zehnder interferometers, which were inherently insensitive to temperature and wavelength. The phase shifters composed of p-i-n diodes were stable against temperature change under a constant bias-current condition. The PD photocurrent was also temperature insensitive, and the photo-to-dark current ratio was higher than 30 dB up to 100 °C. We achieved error-free data links at 20 Gbps and a high bandwidth density of 19 Tbps/cm2 operating up to 125 °C without adjusting the LDs, modulators, or PDs. The interposers are tolerant of the heat generated by the mounted LSIs and usable over the extended industrial temperature range without complex monitoring or feedback controls. The bandwidth density is sufficient for the needs of the late 2010s.