An optical module includes a semiconductor laser with an active layer disproportionately positioned closer to the first surface. The semiconductor laser includes a reflector for reflecting the light outgoing from the active layer in a direction along the first surface toward another direction. The active layer and the reflector are monolithically integrated in the semiconductor laser. The optical module includes a carrier formed from a light transmissive material and having a third surface and a fourth surface opposite to each other. The semiconductor laser is mounted on the carrier so as for the light to enter the third surface. The carrier has a lens integrally on the fourth surface. The optical module includes a substrate having an optical waveguide and an optical coupler for guiding the light to the optical waveguide. The optical waveguide and the optical coupler are integrated in the substrate.

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.

Microwave-frequency signal generation by generating multiple sideband optical signals separated by phase-modulation frequency f.sub.M, generating beat signals between one or two sidebands and one or two optical reference signals, generating a loop-filtered error signal by comparing an electrical reference signal to one of the beat signals or their difference, and controlling with the error signal in a phase-locked loop arrangement a voltage-controlled oscillator (VCO) that drives the sideband generation at the frequency f.sub.M. A portion of the VCO output is the generated microwave-frequency 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 process and system for producing random numbers by means of a quantum random number generator is disclosed, comprising the steps of operating a multimode laser in a laser cavity with periodic modulation of a net gain, and detecting the random intensity pattern produced by the inter-mode beating occurring within the laser cavity. The numbers produced are truly random and a minimal number of elements is required for operating the system.

The present invention is directed to a modulated which includes a semiconductor laser being driven by direct current for frequency tuning, and an AC current with two radio frequencies that can generate repump and Raman frequencies, such that only one laser is needed to produce all the frequencies required to operate an atom interferometer. The present invention is also directed to a method of double modulating a laser to produce all required frequencies for an atom interferometer.

A process and system for producing random numbers by means of a quantum random number generator is disclosed, comprising the steps of operating a multimode laser in a laser cavity with periodic modulation of a net gain, and detecting the random intensity pattern produced by the inter-mode beating occurring within the laser cavity. The numbers produced are truly random and a minimal number of elements is required for operating the system.

A vertical cavity surface emitting laser includes: a laminated body; an insulation layer which is provided over at least a portion of the laminated body; an electrode of which at least a portion is provided over the laminated body; a pad; and a wiring which connects the electrode and the pad, wherein the laminated body includes a first mirror layer, an active layer, and a second mirror layer, the laminated body includes a first distortion imparting portion, a second distortion imparting portion, and a resonance portion which is provided between the first distortion imparting portion and the second distortion imparting portion, in a plan view, the electrode is provided so as to cover at least a portion of the resonance portion, in the plan view, a width of the wiring is greater than a width of the first distortion imparting portion and is smaller than a width of the electrode.