A laser communication apparatus is provided for sending and receiving messages. A processor encodes user messages for a modulator. The modulator provides control signals related to the encoded message to a plurality of seed lasers. Each seed laser can provide light at a different wavelength. Amplifiers are joined to amplify light from the seed lasers. Amplified light is multiplexed together. Multiplexed light is transmitted by a collimating lens along a target vector. A portion of the light can be monitored by a first detector. A telescope receives light from the target vector and provides focused light to a second detector. The second detector provides a signal responsive to the received light to the processor. The processor decodes this signal to provide the received message.

An optical arrangement includes a disk-shaped laser-active medium configured to create an optical gain upon being pumped within a pump volume, and a laser beam incoupler for input coupling a laser beam as a seed laser beam into the laser-active medium. The laser beam interacts with the laser-active medium. The optical arrangement further includes an auxiliary resonator for creating an auxiliary resonator radiation field. The auxiliary resonator radiation field interacts with the laser-active medium. The auxiliary resonator is configured to suppress at least one mode of the auxiliary resonator radiation field that overlaps with at least one mode of the laser beam in the pump volume.

Devices and methods for lessening a thermal dependence of gain profile of an optical amplifier are disclosed. An optical beam is split in a plurality of sub-beams with a thermally variable power splitting ratio, e.g. one sub-beam may travel a longer optical path length than another. When the sub-beams are recombined, they interfere with each other, causing the throughput to be wavelength dependent. An amplitude of this wavelength dependence is thermally variable due to the thermally variable power splitting ratio. The thermally variable power splitting ratio and the optical path length difference are selected so as to offset a thermal variation of a spectral gain profile of an optical amplifier.

The present application is directed to an optical apparatus including an optical waveguide configured to receive an optical signal at an input wavelength. The apparatus also includes one or more optical pump sources connected to transmit pump light to the optical gain medium for the optical gain medium to amplify the optical signal. The apparatus also includes an optical feedback loop for a protection wavelength that includes the optical gain medium and at least a portion of the optical waveguide. A round-trip optical gain of the optical feedback loop is higher at an optical wavelength of the pump light than at the input wavelength less than unity in the presence of the optical signal. In addition, the round-trip gain of the optical feedback loop is greater than or equal to unity in the absence of the optical signal.

Optical frequency combs are used for a wide range of applications, some of which require precise control of the amplitude and phase of individual comb teeth. A technique is provided for tooth-level optical frequency comb control. A frequency comb may include a plurality of comb teeth that are separated from one another by a comb frequency spacing. This technique includes generating a train of control pulses, each of the control pulses being frequency-locked to a corresponding tooth of an optical frequency comb to be controlled. The tooth-level control of the frequency comb is enabled via stimulated Brillouin scattering using the train of control pulses.

An optical amplification device includes: a laser medium that amplifies input light to generate output light; an excitation light source that supplies excitation light used for amplifying the input light, to the laser medium; a resonator that includes a pair of first optical elements and disposed to optically face each other with the laser medium interposed between the first optical elements and that resonates generated light generated in the laser medium through the supply of the excitation light; and an optical switch disposed on an optical path of the resonator between the pair of first optical elements.