Optical attenuator

An optical attenuator for attenuating a light beam, said optical attenuator comprising:

• a plurality of multiple quantum well structures (MQWSs);
• and
• an electro-optical feedback system responsive to said attenuated light beam and electrically connected to said MQWS for regulating the optical absorption of said QWSs;
• and further including an optical demultiplexer for separating said beam into a plurality of different wavelengths.

An optical attenuator for attenuating a light beam, said optical attenuator comprising;

• a multiple quantum well structure MQWS;
• and
• an electro-optical feedback system responsive to said attenuated light beam and electrically connected to said MQWS for regulating the optical absorption of said MQWS;
• wherein said electro-optical feedback system comprises a photodetector for producing a feedback signal, a beam splitter for directing a portion of said attenuated light beam to said photodetector, and an optical demulitiplexer.

An optical attenuator for attenuating a light beam, said optical attenuator comprising:

• a multiple quantum well structure (MQWS);
• and
• an electro-optical feedback system responsive to said attenuated light beam and electrically connected to said MQWS for regulating the optical absorption of said MQWS;
• wherein said electro-optical feedback system comprises a photodetector for producing a feedback signal, a beam splitter for directing a portion of said attenuated light beam to said photodetector, and an optical grating.

An optical attenuator for attenuating a light beam, said optical attenuator comprising:

• a multiple quantum well structure (MQWS);
• and
• an electro-optical feedback system responsive to said attenuated light beam and electrically connected to said MQWS for regulating the optical absorption of said MQWS;
• wherein said electro-optical feedback system comprises a current mirror.

A method of attenuating a light beam, said method comprising:

• providing a plurality of multiple quantum well structures (MQWSs), each of said MQWSs designed to attenuate at a different wavelength;
• separating a beam of light into a plurality of subbeams, each subbeam having a different wavelength;
• directing each of said subbeams onto the one at said MQWSs designed to attenuate the corresponding wavelength;
• attenuating said light beams in said MQWSs;
• exiting said light beams from said MQWSs;
• directing a portion of said exit light beams onto a photodetector to provide feedback signals and
• utilizing said feedback signals to regulate the current in, and thus the attenuation of, said MQWSs.