In one embodiment, an electro-absorption modulator is configured to receive an optical light from an optical light source and outputs a modulated optical signal. The electro-absorption modulator includes a bias voltage that is used to set optimum predetermined modulation performance and an output power of the electro-absorption modulator. A controller is configured to measure a bias current of the optical light source and use a change of the bias current to determine a detuning change that occurs between the electro-absorption modulator and the optical light source. The controller uses the detuning change to automatically control the bias voltage of the electro-absorption modulator to maintain the predetermined modulation performance and maintain the output power of the electro-absorption modulator.

Device, system, and method of aircraft protection and countermeasures against threats. A system for protecting an aircraft against a threat, includes a dual frequency Radio Frequency (RF) module, which includes: a dual-band RF transmitter and a dual-band RF receiver, to transmit and receive high-band RF signals and low-band RF signals; and a threat confirmation and tracking module, to confirm and track a possible incoming threat based on processing of high-band RF signals and low-band RF signals received by the dual-band RF receiver. The system further includes a dual frequency band antenna, to transmit and receive the high-band RF signals and the low-band RF signals. The system also includes a directed high-power laser transmitter, to activate a directed high-power laser beam as countermeasure towards a precise angular position of a confirmed threat.

In one embodiment, a lidar system includes a light source configured to emit light at one or more wavelengths between 1200 nm and 1400 nm. The lidar system also includes a scanner configured to scan the emitted light across a field of regard of the lidar system and a receiver configured to detect a portion of the emitted light scattered by a target located a distance from the lidar system. The lidar system further includes a processor configured to determine the distance from the lidar system to the target based at least in part on a round-trip time for the portion of the emitted light to travel from the lidar system to the target and back to the lidar system.

Various optical systems equipped with diode laser light sources are discussed in the present application. One example system includes a diode laser light source for providing, a beam of radiation. The diode laser has a spectral output bandwidth when driven under equilibrium conditions. The system further includes a driver circuit to apply a pulse of drive current to the diode laser. The pulse causes a variation in the output wavelength of the diode laser during the pulse such that the spectral output bandwidth is at least two times larger the spectral output bandwidth under the equilibrium conditions.

A reflectarray metasurface for quantum-cascade lasing includes: (1) a substrate; and (2) an array of subcavities disposed on the substrate. Each subcavity in the array of subcavities includes (a) a first metallic layer disposed on the substrate; (b) a layer of a quantum-cascade laser active material disposed on the first metallic layer; and (c) a second metallic layer disposed on the layer of the quantum-cascade laser active material. At least some subcavities in the array of subcavities have inhomogeneous widths, and the array of subcavities is configured to reflect an incident light of at least one resonant frequency with amplification.

A method of controlling a laser unit in order to negate heat build-up caused by a laser modulation current, and eliminating artifacts caused by image related thermal effects. Upon receipt of an activation signal, an activation current is applied which causes lasing of the laser unit. Upon receipt of a deactivation signal, the method ceases lasing by selectively applying either an idle current below the activation current, or a cooling current below the idle current.

A method for controlling a wavelength of an optical module, includes: a laser light source unit emitting a laser beam; a wavelength filter having a periodical transmission characteristic with respect to a wavelength of light; a temperature controller on which the wavelength filter is placed and that adjusting a temperature of the wavelength filter; a heat generating body placed on the temperature controller; and a control device controlling the wavelength of the laser beam emitted from the laser light source unit and control the transmission characteristic of the wavelength filter based on an intensity of the laser beam transmitted through the wavelength filter, the method including changing at least one of a target value of the wavelength control of the laser beam and a target value of the control of the wavelength filter based on a current value of the heat generating body.

Optical gain media and gain devices are required for lasing devices and high intensity optical systems across a wide range of application. A compact optical gain device that provides near-infrared and infrared lasing at room temperature includes an optical microcavity having a refractive index and a curvilinear outer surface with an angle of curvature such that the optical microcavity supports the propagation of an electromagnetic whispering gallery mode. A plurality of optical gain structures are disposed along the curvilinear outer surface of the optical microcavity, the each of the optical gain structures having an optically active wavelength range over which each of the corresponding optical gain structures provides optical gain to radiation through stimulated emission.

In an example, the present invention provides a small form factor package comprising RGB laser diode devices configured with short cavity lengths. In an example, the present laser module includes at least a first red laser diode device, at least a second green laser diode device, and at least a third red laser diode device. At least one of the laser diode devices has a cavity length of less than 200 um, or less than 150 um, or less than 100 um. The optical output beams of the red, green, and blue laser diodes are combined into a single beam or colinear beams using optical techniques. The laser diode devices and the optical combining optics contained in a sealed package device. The sealed package device has a small form factor volume.

A laser device includes a laser oscillator, a dehumidifier, and a controller controlling an operation of the dehumidifier. The controller controls the dehumidifier such that the dew point inside the laser oscillator is lower than the first dew point when a monolayer or less of water molecules is adsorbed, or such that the dew point is equal to or higher than the second dew point when more than a monolayer of water molecules is adsorbed inside the laser oscillator, and is lower than the third dew point at which the dew condensation starts to occur inside the laser oscillator.