34results about How to "Wide modulation bandwidth" patented technology

A solid state device used to modulate the intensity of reflected or transmitted light by modulating with an external voltage the optical thickness of a thin film ferroelectric placed in an etalon cavity is disclosed. The device is constructed by selecting a generally planar supporting substrate, preferably silicon or sapphire in order to be compatible with silicon integrated circuits. A dielectric stack consisting of alternating layers of different index of refraction materials, also specifically selected to be compatible with later growth of the thin film ferroelectric, is deposited thereon to form a partially reflective and partially transmitting mirror, followed by a transparent electrically conductive layer. The thin film ferroelectric is deposited on the conductive layer, followed by a second transparent conductive layer and a second dielectric stack. Leads are connected to the conductive layers and in turn to a voltage generator. In one version of the invention, the functions of both the second (top) electrically conductive layer and dielectric stack are fulfilled by using a semi-transparent conducting film. In another version, the functions of both the first (bottom) electrically conductive layer and dielectric stack are also fulfilled by using a, preferably, highly reflective conducting film.

The invention relates to a cross-polarization laser feedback grating interferometer of a phase modulation type, and a measurement method thereof. The measurement principle is based on the grating diffraction, optical Doppler effect, Lamb semi-classical theory and time-domain orthogonal demodulation principle. The orthogonally polarized light outputted by a birefringent dual-frequency helium-neon laser is perpendicularly incident to a polarization beam splitting prism and is divided into two linearly polarized light beams in different polarization directions. The two polarized light beams respectively pass through two different electrooptical modulators and then are respectively reflected by a reflector at a + / -1-order Littrow incidence angle to a reflection-type diffraction grating. The diffracted light returns to the laser cavity along the respective incident light, and performs self-mixing interference with the light in the cavity. The backward output light of the laser passes through a polarizer and then only the single-mode light is retained and accepted by a photodetector. An output signal of the photodetector is outputted to a data processing module for data processing, and the two-dimensional displacement of a target to be measured is obtained. The grating interferometer has the advantages of simple structure, large measuring range and high measurement resolution.

The invention relates to a metamaterial modulator, comprising a surface layer, a graphene layer, a first flexible dielectric layer, a perovskite layer, a metal structure layer, a second flexible dielectric layer and an underlying substrate layer arranged from top to bottom; The structural layer is composed of several metal structures. During the modulation process, the electrical conductivity of the graphene layer and the perovskite layer is changed due to the incidence of laser light, and the incident terahertz wave is regulated twice. At the same time, the graphene layer and the surface layer have electrodes, thereby It is also possible to conduct multi-material optoelectronic joint regulation of terahertz waves through electric fields. During the modulation process, the metal structure interacts with terahertz waves to generate resonance, increasing the modulation depth.

The invention discloses a ring resonant cavity optical modulator based on a graphene microstrip line traveling wave electrode, which belongs to the field of optoelectronic technology, and solves the problem that the graphene-based optical modulator is limited by the larger RC of the lumped electrode structure in the prior art. Constant, resulting in a relatively small modulation bandwidth, a ring resonator optical modulator based on graphene microstrip line traveling wave electrodes is provided. The present invention comprises a substrate layer, a strip optical waveguide and a ring optical waveguide arranged on the surface of the substrate layer, the strip optical waveguide divides the surface of the substrate layer into two parts, and the ring optical waveguide is arranged on one side of the strip optical waveguide On both sides of the strip optical waveguide, a first dielectric filling layer and a second dielectric filling layer are arranged on the surface of the substrate layer, and a microstrip line traveling wave electrode structure is arranged on the ring optical waveguide. The present invention is used for Achieving light modulation rate.