Monday, August 31, 2009

US Patent 7580595 - Optical frequency modulation using quantum laser

http://www.freepatentsonline.com/7580595.html

This patent teaches a laser based on quantum confinement achieving high speed operation with reduced parasitic electrical effects. Claim 1 reads:

1. A data transmission optoelectronic device, comprising:

mirrors providing feedback for light;

a waveguide disposed between said mirrors;

an active section incorporated in said waveguide, said active section having an active element for generating an optical gain if a forward bias is applied, said active element being selected from the group consisting of: a) a quantum well; b) an array of quantum wires; c) an array of quantum dots; d) a stack of quantum wells, quantum wires, or quantum dots; and e) any combination of a) through d);

an absorption section incorporated in said waveguide; and

an additional modulator incorporated in said waveguide, said additional modulator being configured to modulate a refractive index thereof such that a repetition frequency of the pulsed laser light is frequency-modulated and frequency-modulated optical data signals are generated; wherein the device is operable in a pulsed regime emitting pulsed laser light and the device is adapted to transmit frequency-modulated data signals.