The present disclosure relates generally to a device, such as a wearable display device configured with a laser diode driver implementing dynamic voltage control for laser diodes. The laser diodes may include one or more of a red laser diode, a blue laser diode, and a green laser diode. The device may determine a load condition based on a frame to be displayed at the device, and determine a target voltage level for a laser diode operably coupled to the laser diode driver of the device based on the load condition (e.g., an image signal processor (ISP) frame buffer load). The device may generate the target voltage level for the laser diode based on a base voltage level. For example, the device may be configured with a voltage booster operably coupled to the laser diode driver to provide the target voltage level in addition to the base voltage level.

The present invention relates to a method for operating a pulsed diode-pumped solid-state laser comprising: providing a pump light source for pumping a solid-state laser, said pump light source comprising at least one laser diode unit configured for emitting a series of light pulses for pumping the solid-state laser, modulating the series of light emission pulses of the at least one laser diode unit such that only the light pulses with a frequency close to or equal to a requested frequency setting of the solid-state laser are operated with a/the required pulse amplitude and/or a/the required pulse duration to trigger light emission of the solid-state laser, and such that any other light pulses of the at least one laser diode unit are operated to not trigger light emission of the solid-state laser.

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.

The invention provides a dynamically swept tunable laser system and method for measuring sensor characteristics obtained from an array of optical sensors comprising means for dividing the total wavelength sweep of the laser into different regions in any particular order where each region contains single or multiple contiguous sweep segments and where each sweep segment is referenced by a start and a stop reference and can have different lengths compared to the other sweep segments. The sensor characteristics are determined from each region swept by the tunable laser. The invention provides for the tunable laser to be adapted to operate in a quasi-continuous mode to select segments in any order. The relative sweep rates of regions can be changed such that some regions can be swept more times than other regions.

A power control system comprising a laser driver that receives a data signal, and responsive to a modulation control signal and a bias control signal, processes the data signal to drive a laser to generate an optic signal that represents the data signal. A monitor photodiode configured to receive the optic signal and generate a monitor photodiode signal.

A modulation control path, that processes a monitor photodiode signal and a reference signal, including at least one filter and at least one mixer. The modulation control path generates a modulation control signal. A bias control path, that processes the monitor photodiode signal and the reference signal, that includes at least one filter and at least one average weighting module to generate a modulation control signal. The bias control path and the modulation control path processing reduces the effect of the error in the monitor photodiode signal.

A tunable laser includes a semiconductor optical amplifier (SOA) having a reflective end coupled to a shared reflector and an output end, which is coupled to a demultiplexer through an input waveguide. The demultiplexer comprises a set of Mach-Zehnder (MZ) lattice filters, which function as symmetric de-interleaving wavelength splitters, that are cascaded to form a binary tree that connects an input port, which carries multiple wavelength bands, to N wavelength-specific output ports that are coupled to a set of N reflectors. A set of variable optical attenuators (VOAs) is coupled to outputs of the MZ lattice filters in the binary tree, and is controllable to selectively add loss to the outputs, so that only a single favored wavelength band, which is associated with a favored reflector in the set of N reflectors, lases at any given time. An output waveguide is optically coupled to the lasing cavity.

One or more embodiments are directed to laser circuits, methods and devices that include a current sensing circuit for sensing a lasing current provided to a laser diode or device. One embodiment is directed to a circuit that includes a laser device, a switching device, a current sensing circuit and a current comparator. The switching device has a first conduction terminal coupled to the laser device and a second conduction terminal coupled to a supply voltage. The switching device is configured to operatively supply a lasing current to the laser device. The current sensing circuit is coupled to the switching device and is configured to generate a sense current representative of the lasing current. The current comparator is configured to receive the sense current from the current sensing circuit, to receive a reference current, and to compare the sense current with the reference current. If the sense current exceeds the reference current, the current comparator is configured to output an overcurrent detection signal.

A tunable laser includes a reflective silicon optical amplifier (RSOA) with a reflective end and an interface end and an array of narrow-band reflectors, which each have a different center wavelength. It also includes a silicon-photonic optical switch, having an input port and N output ports that are coupled to a different narrow-band reflector in the array of narrow-band reflectors. The tunable laser also includes an optical waveguide coupled between the interface end of the RSOA and the input of the silicon-photonic optical switch. The frequency of this tunable laser can be tuned in discrete increments by selectively coupling the input port of the silicon-photonic optical switch to one of the N output ports, thereby causing the RSOA to form a lasing cavity with a selected narrow-band reflector coupled to the selected output port. The tunable laser also includes a laser output optically coupled to the lasing cavity.

A power control method for a laser system comprising laser diodes arranged in diode banks is provided. Each diode bank comprises at least one of the laser diodes and has a maximum power. The method comprises operating a first diode bank of the diode banks to output a first power; and concurrently operating other of the diode banks to output other powers, at least one of the other powers being different than the first power.