6 results about "Directly modulated laser" patented technology

This invention relates to a machine learning-based modeling method for cloud wireless access networks, comprising: acquiring a remote cloud wireless access network transmitter; improving the remote cloud wireless access network transmitter by replacing the traditional microwave source with a dual-ring opto-oscillator to suppress side modes through single-mode oscillation; and introducing a directly modulated laser after an arbitrary waveform generator to utilize the chirp effect and fiber dispersion to generate power gain; and modeling the millimeter-wave signal spectrum of the improved remote cloud wireless access network transmitter based on a lightweight gradient booster model to match the dimensions of input and output features. This invention uses a dual-ring opto-oscillator to replace the traditional microwave source, reducing phase noise; utilizes the synergistic gain behavior of the directly modulated laser chirp and fiber dispersion to improve the transmission gain of the millimeter-wave signal; and models the spectral characteristics of the millimeter-wave signal using a lightweight gradient booster model to achieve spectrum prediction.

A laser includes a substrate, a first cladding and a second cladding, a gain medium, and a plurality of supports. The first cladding is spaced apart from the substrate by an air gap. The first cladding has a thickness in a vertical direction in a range from 0.05 microns to 0.15 microns. The gain medium is disposed on the first cladding opposite the air gap. The second cladding is disposed on the gain medium opposite the first cladding. The second cladding has a thickness in the vertical direction in a range from 0.05 microns to 0.15 microns. The supports are coupled to each of the substrate, the first cladding, the gain medium, and the second cladding to hold the first cladding, the gain medium, and the second cladding spaced apart from the substrate.

An H-bridge integrated laser driver optimizes power consumption, impedance matching, low-swing and high-swing reliability for electro-absorption modulated laser (EML) and direct modulated laser diode (DML) applications, VCSEL / silicon photonics, and other applications requiring high-swing drivers or control of impedance. The laser driver includes a retimer for converting low-speed parallel data into a high-speed serial bit stream and an inverted representation of the high-speed parallel bit stream, an M-bit PMOS DAC configured to receive a first buffered bit stream, an N-bit NMOS DAC configured to receive a second buffered bit stream substantially synchronized with the first buffered bit stream. A protection device is coupled between the M-bit DAC and the N-bit DAC. A first DC level shift pre-driver array is coupled between the retimer and the M-bit DAC to receive the high-speed parallel bit stream and the inverted high-speed parallel bit stream, and a second DC level shift pre-driver array is coupled between the retimer and the N-bit DAC to receive the high-speed parallel bit stream and the inverted high-speed parallel bit stream. An impedance matching module is coupled to an output of the protection device. The laser driver can be integrated on a CMOS communication chip.

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 invention discloses a nonlinear distortion suppression method and device for an optical single-side-band transmitter based on an electro-absorption modulated laser. A digital pre-distortion model containing second-order nonlinearity and intermodulation distortion of a direct modulated laser and an electro-absorption modulator is established in a digital domain; and a cost function is constructed in combination with an actual output spectrum, and a model coefficient is adaptively iteratively updated, so that the optical single-side band signal output by the transmitting end realizes forward compensation on a main nonlinear component before transmission, and the transmission efficiency is improved on the premise that an additional optical device and a complex receiving end balance structure are not required to be increased. According to the optical single-side-band transmitter, nonlinear distortion and intermodulation distortion caused by cascade modulation are effectively suppressed, the linearity and the adjacent channel power ratio of the optical single-side-band signal are remarkably improved, the signal-to-noise ratio and the bit error rate performance of the system are improved, and the transmission capacity and the engineering practicability of the optical single-side-band transmitter in a medium-long-distance high-speed optical interconnection scene are enhanced.

The invention discloses a laser radar signal generation method, a laser radar signal detection method and a laser radar signal detection system. The system comprises a transmitting end and a receiving end, the transmitting end comprises a transmitting end modulation module used for generating a first electric driving signal and a target modulation reference signal; the direct modulation module directly modulates the first electric driving signal to generate a calibration electric signal; the pre-distortion equalization module compares the calibration electric signal with the modulation reference signal to generate a second electric driving signal; the beam transmitting module adopts a second electric driving signal to drive a direct modulation laser to generate radar detection signal light to be transmitted; the receiving end comprises a beam receiving module used for receiving reflected signal light after the radar detection signal light is reflected by a target; the coherent detection module performs coherent mixing on the reflected signal light and the transmitted signal light to obtain an electric signal; the phase recovery module obtains a signal after phase recovery according to the electric signal; the distance analysis module estimates the distance of the target; the Doppler processing module estimates a relative velocity of the target.