H01S5/0261

Pulsed laser diode driver

A pulsed laser diode driver includes an inductor having a first terminal configured to receive a source voltage. A source capacitor has a first terminal connected to the first terminal of the inductor to provide the source voltage. A bypass switch has a drain node connected to a second terminal of the inductor and to a first terminal of a bypass capacitor. A laser diode switch has a drain node connected to the second terminal of the inductor. A laser diode has an anode connected to a source node of the laser diode switch and a cathode connected to a bias voltage node. The laser diode switch and the bypass switch control a current flow through the inductor to produce a high-current pulse through the laser diode, the high-current pulse corresponding to a peak current of a resonant waveform developed at the anode of the laser diode.

PULSED RESONANT LASER DIODE ARRAY DRIVER

A pulsed laser diode array driver includes an inductor having a first terminal configured to receive a source voltage, a source capacitor coupled between the first terminal of the inductor and ground, a bypass capacitor connected between a second terminal of the inductor and ground, a bypass switch connected between the second terminal of the inductor and ground, a laser diode array with one or more rows of laser diodes, and one or more laser diode switches, each being connected between a respective row node of the laser diode array and ground. The laser diode switches and the bypass switch are configured to control a current flow through the inductor to produce respective high-current pulses through each row of the laser diode array, each of the high-current pulses corresponding to a peak current of a resonant waveform developed at that row of the laser diode array.

Integrated Laser Source

Integrated laser sources emitting multi-wavelengths of light with reduced thermal transients and crosstalk and methods for operating thereof are disclosed. The integrated laser sources can include one or more heaters and a temperature control system to maintain a total thermal load of the gain segment, the heater(s), or both of a given laser to be within a range based on a predetermined target value. The system can include electrical circuitry configured to distribute current to the gain segment, the heater(s), or both. The heater(s) can be located proximate to the gain segment, and the distribution of current can be based on the relative locations. In some examples, the central laser can be heated prior to being activated. In some examples, one or more of the plurality of lasers can operate in a subthreshold operation mode when the laser is not lasing to minimize thermal perturbations to proximate lasers.

Independent control of emission wavelength and output power of a semiconductor laser

Methods for driving a tunable laser with integrated tuning elements are disclosed. The methods can include modulating the tuning current and laser injection current such that the laser emission wavelength and output power are independently controllable. In some examples, the tuning current and laser injection current are modulated simultaneously and a wider tuning range can result. In some examples, one or both of these currents is sinusoidally modulated. In some examples, a constant output power can be achieved while tuning the emission wavelength. In some examples, the output power and tuning can follow a linear relationship. In some examples, injection current and tuning element drive waveforms necessary to achieve targeted output power and tuning waveforms can be achieved through optimization based on goodness of fit values between the targeted and actual output power and tuning waveforms.

METHODS AND DEVICES FOR AN ELECTRICALLY EFFICIENT GREEN LASER DIODE DRIVE SYSTEM WITH BOOST SERVO

Methods and devices for driving a laser diode are disclosed herein. An example method includes a boost regulator outputting a maximum boost voltage to drive a laser diode that is configured to output light within a wavelength range of 495 nanometers (nm) to 570 nm. A boost servo may measure a laser voltage, and calculate a voltage difference between the two voltages. The servo may then compare the voltage difference to a drive voltage to determine an excess voltage, and may cause the boost regulator to output an optimum voltage based on the excess voltage. The boost servo may also calculate a low voltage to drive at least one additional component that is electrically coupled to the boost regulator when the laser diode is inactive; and may cause the boost regulator to output the low voltage to power the at least one additional component.

Light Source for Frequency-Modulated Continuous Wave (FMCW) LiDAR Device
20220334225 · 2022-10-20 ·

A light source for a frequency-modulated continuous-wave (FMCW) LiDAR device is formed by a photonic integrated circuit and comprises a substrate and a multilayer structure. Formed in the multilayer structure is a semiconductor laser that is received in a recess etched into the multilayer structure. An optical path between the semiconductor laser and a reflector forms an external cavity for the semiconductor laser. The external cavity includes a variable attenuator causing an attenuation of light guided in the cavity optical waveguide. The external cavity may also or alternatively include an optical phase modulator.

LIGHT-EMITTING DEVICE AND MEASUREMENT DEVICE

A light-emitting device includes: plural light-emitting units; a driving unit that drives the light-emitting units by supplying a current to the light-emitting units; and a switching unit that is provided on a side opposite to a side where the driving unit is provided relative to the plural light-emitting units and switches light emission of the plural light-emitting units.

INTRACAVITY PUMPED PASSIVELY Q-SWITCHED LASER
20230104691 · 2023-04-06 ·

A passively Q-switched laser with intracavity pumping is described. The passively Q-switched laser has an optically pumped gain element and a saturable absorber element. The optically pumped gain element is situated in an extended cavity of a VECSEL (Vertical Extended Cavity Surface Emitting Laser) so that the gain element is pumped by a circulating pump beam of the VECSEL. The passively Q-switched laser may produce output pulses at an eye-safe wavelength using a low gain laser transition and may use a plurality of surface emitting gain regions to pump the passively Q-switched laser.

OPTICAL DEVICE HAVING A LIGHT-EMITTING STRUCTURE AND A WAVEGUIDE INTEGRATED CAPACITOR TO MONITOR LIGHT
20230143150 · 2023-05-11 ·

Examples described herein relate to an optical device with an integrated light-emitting structure to generate light and a waveguide integrated capacitor to monitor light. The light-emitting structure may emit light upon the application of electricity to the optical device. The waveguide integrated capacitor may be formed under the light-emitting structure to monitor the light emitted by the light-emitting structure. The waveguide integrated capacitor includes a waveguide region carrying at least a portion of the light. The waveguide region includes one or more photon absorption sites causing the generation of free charge carriers relative to an intensity of the light confined in the waveguide region resulting in a change in the conductance of the waveguide region.

NEGATIVE BIAS TO IMPROVE PHASE NOISE
20230208100 · 2023-06-29 ·

A method of operating an optoelectronic device comprising an optical waveguide section, the optical waveguide section comprising a semiconductor core, the method comprising the steps of determining (401) a range for a negative bias voltage for the waveguide section for which an optical loss of the core is lower than an optical loss at zero bias for an operating wavelength range of the device, selecting (402) a bias voltage within the range and applying (403) the selected bias voltage to the waveguide section.