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.

A window material for protecting near infrared light emitting lasers and or detectors is coated with a conductive coating that reduces the reflection at the wavelengths and angles of incidence of interest. The conductive coating allows the window to be heated by applying a bias across connected electrodes to remove or prevent the condensation of liquid water and the buildup of ice. The conductive material in the coating has some optical absorption in the hear infrared region of about 800 to 1600 nm, which in combination with multiple intervening dielectric layers also allows the transmission of 90% of the light while obtaining a resistance of less than about 30 Ohms-square. The coating reduces reflection loses from the window, without decreasing transmission by more that about 10%.

A laser diode drive system configured to output a drive signal to control a voltage provided to a laser diode can include a circuit sensor system configured to output a sensed signal indicative of a drive current of a laser diode, and a temperature sensor configured to output a temperature signal indicative of a temperature of the laser diode or an ambient temperature of the laser diode. The system can include a temperature compensation system configured to output a correction signal based on the temperature signal to compensate for a temperature dependent factor in the sensed signal.

A method for physical random number generation includes the steps of: modulating the gain of a vertical-cavity surface-emitting laser periodically from the lower threshold to the upper threshold and back; maintaining the gain per round trip positive for a longer period than the round trip time of the cavity; maintaining the net gain per round trip negative for a longer period than the round trip time of the cavity, in order to create optical pulses of random amplitude; detecting the optical pulses; converting the optical pulses into electrical analog pulses; and digitising the electrical analog pulses into random numbers.

A light emitting device includes: a light emitting element; and a wavelength conversion member including: a wavelength conversion part configured to convert light emitted from the light emitting element into light having a different wavelength and to output the light having the different wavelength, an enclosing part enclosing the wavelength conversion part, and a conducting layer disposed on the enclosing part and surrounding the wavelength conversion part. The conducting layer comprises ruthenium oxide.

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.

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 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.

A laser display system 100 is configured to increase the dynamic range of a laser diode by modulating an operating current applied to the laser diode based on a desired sequence of brightness levels and a temperature of the laser diode. In some embodiments, a measuring circuit measures a voltage of the laser diode at a given current, which indirectly indicates the temperature of the laser diode, thus obviating the need for a direct measurement of temperature. In addition, in some embodiments, the measuring circuit identifies a threshold current of the laser diode based on a range of current values at which values of the current multiplied by the derivative of the voltage against the current vary relatively rapidly. By compensating for temperature effects and identifying the threshold current, a driver of the laser diode more precisely controls light output of the laser diode across an increased dynamic range.

A light source device with a safety mechanism includes a wavelength converting device and a laser light source configured to provide a laser beam. The wavelength converting device includes a substrate facing toward the laser light source, an optical converting layer disposed on the substrate, and a safety examination layer disposed on one side of the optical converting layer. After the laser beam passes through the safety examination layer, the laser beam enters the optical converting layer. The safety examination layer includes a first conductive film arranged along a first direction and a second conductive film arranged along a second direction. The first conductive film and the second conductive film intersect each other.