5results about How to "High modulation rate" patented technology

The application provides a radio frequency source circuit and a laser frequency shift lock cavity signal generation method, which can be applied to the field of cold atom optical lattice clock technology. The radio frequency source circuit comprises a control sub-circuit, a phase-locked loop sub-circuit and an output power control sub-circuit. The control sub-circuit is used for receiving a digital control instruction from an upper computer and taking a synchronous clock as a working clock, performing amplitude-phase conversion and phase waveform conversion in parallel based on preset modulation data carried by the digital control instruction, and outputting a phase control word and a phase demodulation signal. The phase-locked loop sub-circuit is used for frequency multiplication of a reference clock and outputting a clock signal suitable for the working frequency of a frequency synthesizer as the working reference clock of the frequency synthesizer. The frequency synthesizer is used for taking the working reference clock as a frequency reference, realizing phase synchronization by combining the synchronous clock, and adjusting the phase of an output signal based on the phase control word. The output power control sub-circuit is used for adjusting the power of the output signal of the frequency synthesizer based on preset power modulation data to output a laser frequency shift lock cavity signal.

The invention provides a directly modulated laser, which comprises a substrate, an epitaxial layer, a buffer layer, a grating layer, a lower limiting layer, an active layer, an upper limiting layer, a corrosion cut-off layer, a cladding and a contact layer, the structure of the grating layer is a convex grating structure with a lambda / 8 phase shift, the grating layer is located on the N-type doped side, and the convex grating structure with the lambda / 8 phase shift is used for reducing the photon density at the phase shift position through the negative reflector loss feedback effect and limiting hole gathering on the P-type doped side through the characteristic that the electron mobility is larger than the hole mobility.

The application provides a high-speed, high-efficiency and low-cost semiconductor optical communication device and a preparation method thereof. The high-speed, high-efficiency and low-cost semiconductor optical communication device comprises a first Bragg reflector, first to Nth active layers arranged in sequence along a first direction on one side of the first Bragg reflector, wherein N is an integer greater than or equal to 2; first to N-1th tunnel junctions, wherein any nth-1th tunnel junction is located between an nth-1th active layer and an nth active layer, n is an integer greater than or equal to 2 and less than or equal to N; first to N-1th current limiting layers arranged along the first direction, wherein any nth-1th current limiting layer is located on the side of the nth-1th tunnel junction along a second direction, and the nth-1th current limiting layer has an overlapping projection on the sidewall of the nth-1th tunnel junction along the second direction; and wherein the second direction is perpendicular to the first direction.

The laser chip fabrication method and laser chip disclosed herein include a light-emitting region and an electro-absorption modulation region. The P-InP layer includes a first region, a second region, and a third region, with a second active region located below the third region. The first and second regions are exposed to the implanted ion beam, forming a first and a second electrically isolated region. The third region, protected by a mask, remains conductive, forming a first P-InP body layer. During ion implantation, the first and second metal layers act as masks for the first P-InP body layer, intercepting ion implantation and preventing ions from penetrating deep into the first P-InP body layer, thus maintaining its conductivity. The narrow linewidths of the first and second metal layers reduce the ion implantation width of the first P-InP body layer, resulting in a narrower linewidth first P-InP body layer, which is beneficial for improving the modulation rate and modulation bandwidth of the electro-absorption modulation region.

This invention provides a thermo-optical phase shifter array and its formation method, comprising: forming multiple waveguides, wherein the multiple waveguides have the same length in a first direction and the same width in a second direction, and the first and second directions are perpendicular to each other; forming electrodes on the surface of each waveguide, wherein the area of ​​the multiple electrodes on the plane formed by the first and second directions gradually increases along the second direction; forming a dielectric layer on the surface of each electrode, the dielectric layer filling the gaps between adjacent electrodes and adjacent waveguides; forming isolation trenches in the dielectric layer and buried oxide layer on both sides of each waveguide along the second direction and in the underlying silicon layer below each waveguide, wherein the waveguides and the buried oxide layer below the waveguides are suspended on the isolation trenches, and the area of ​​the multiple isolation trenches located below the waveguides on the plane formed by the first and second directions gradually decreases along the second direction. This invention achieves a balance between modulation rate and modulation efficiency while satisfying the phase shift requirement.