Systems and methods described herein are directed to optical light sources, such as an external cavity laser (ECL) with an active phase shifter. The system may include control circuitry for controlling one or more parameters associated with the active phase shifter. The phase shifter may be a p-i-n phase shifter. The control circuitry may cause variation in a refractive index associated with the phase shifter, thereby varying a lasing frequency of the ECL. The ECL may be configured to operate as a light source for a light detection and ranging (LIDAR) system based on generating frequency modulated light signals. In some embodiments, the ECL may generate an output LIDAR signal with alternating segments of increasing and decreasing chirp frequencies. The ECL may exhibit increased stability and improved chirp linearities with less dependence on ambient temperature fluctuations.

A transmitter unit for emitting radiation into the surrounding area, including at least one semiconductor laser, which has at least one first emitter possessing a first section and a second section; and at least one control unit for controlling the semiconductor laser. The control unit is configured to apply a first supply variable to the first section of the at least one emitter, and to apply a second supply variable differing from the first supply variable, to the second section of the at least one emitter.

A drive circuit that includes a switching circuit switching between a first state and a second state to cause a light-emitting element to perform pulse oscillation, and a direct current adjustment circuit. In the first state, light is emitted from a light-emitting element by supplying the light-emitting element with a current having a magnitude equal to or greater than a threshold current enabling the light-emitting element to emit light having an output equal to or greater than a predetermined output. In the second state, the magnitude of the current supplied to the light-emitting element is less than the threshold current. The direct current adjustment circuit supplies, to the light-emitting element, a bias current within a range less than the threshold current of the light-emitting element in the second state. The bias current has a magnitude corresponding to a magnitude of undershoot occurring at a falling edge of the pulse oscillation.

Systems and methods for controlling laser modulation in burst communications. In a start-up phase, a drive circuitry sequentially applies first and second drive currents to a laser diode such that it produces a first and second optical output, respectively. A compensating current source coupled to the laser diode provides a current related to the first and second drive currents to maintain a combined current flowing through an impedance connected to the laser diode at a substantially constant level during the start-up phase. An optical sensor measures the first and second optical outputs, and a controller uses values of the first and second drive currents, the outputs from the optical sensor, and at least one supplied input value to provide control values for the drive circuitry for controlling operating current of the laser diode during a subsequent operating phase, wherein information is transmitted in at least one burst.

An image drawing apparatus includes a light source unit that outputs a laser light, a sensor that measures an index regarding brightness of the laser light, a scanner that reflects and scans the laser light, and an image processor that controls the light source unit, outputs the laser light to a drawing area narrower than a scanning area of the scanner so that an image based on image data that has been input is drawn, outputting an adjustment laser light to adjust the brightness of the laser light to an outside of the drawing area, stops the output of the adjustment laser light when a period (e.g., variable) until the time the output of the adjustment laser light becomes stable is passed after the output of the adjustment laser light is started, and adjusts the laser light brightness based on the index regarding the adjustment laser light brightness.

A surface emission laser driving method according to an embodiment of the present technology includes the following two steps. (A) Generating drive pulses to be sequentially outputted to, out of a plurality of surface emission lasers disposed on a same substrate, each of the surface emission lasers selected as light-emission targets, on the basis of the number of surface emission lasers selected as the light-emission targets and a monitoring temperature that is immediately prior to light emission of each of the surface emission lasers selected as the light-emission targets. (B) Outputting the generated drive pulses to each of the surface emission lasers selected as the light-emission targets.

A driver circuit for a laser diode is configured to pass a current. The circuit includes a charge-pump configured to generate an output boosted positive supply rail voltage. At least one switch is configured to couple the output of the charge-pump to a terminal of the laser diode and to isolate the positive supply rail from the terminal of the laser diode when the charge-pump is enabled.

A laser beam generation device includes power supply units, LD modules, a combiner, and a control device. The LD modules receive currents from the power supply units, and output laser beams. The combiner collects the laser beams and outputs one laser beam. The control device generates control signals such that power of the laser beam becomes a laser output setting value and such that the currents become current command values. Phases of pulses of the control signals are shifted from each other by 60 degrees.

A data transmission method including the step of controlling excitation current for a laser diode of a laser beam emitter device by servocontrolling the excitation current on laser beam power and by modulating the excitation current as a function of the data for transmission in order to encode the data with laser beam power levels, the method being characterized in that it includes the step of measuring a temperature (T.sub.INT) in the vicinity of the laser diode in order to perform, in accordance with the invention, two modes of operation having different setpoint values.

A light emission apparatus includes a transistor comprising a control terminal, a first channel terminal, and a second channel terminal, wherein the control terminal is configured to receive a modulation signal, the first channel terminal is configured to generate a driving signal according to the modulation signal, and the second channel terminal is coupled to a fixed voltage; and a load comprising: a first terminal; a second terminal, wherein the first terminal is coupled to the first channel terminal of the transistor and the second terminal is coupled to the fixed voltage; a laser diode configured to emit a light according to the driving signal; and a first capacitor coupled to the laser diode, configured to isolate a DC current on the first terminal of the transistor.