Telecommunications – Receiver or analog modulated signal frequency converter – Signal selection based on frequency
Patent
1986-06-24
1988-02-02
Orsino, Jr., Joseph A.
Telecommunications
Receiver or analog modulated signal frequency converter
Signal selection based on frequency
370 2, H04B 900
Patent
active
047233150
ABSTRACT:
A method of mixing light from a signal source with light from a local oscillator for heterodyne or homodyne detection using differential detection techniques is described. In the method and apparatus of the invention, incoming light is matched to the polarization of the local oscillator no matter what the polarization of the incoming light is. A sequence of three polarization beamsplitters is utilized to achieve this match. The local oscillator signal and the incoming signal are incident on separate faces of a first polarization beamsplitter. Each is divided into two beams by that beamsplitter and paired with the orthogonally polarized component of the other, each signal/local oscillator pair exiting from one exit face of the first polarization beamsplitter. The second polarization beamsplitter resolves one of these pairs into sum and difference pairs of matched polarization which interfere and are detected by square law detectors, forming currents which are subtracted in a differential amplifier. The third polarization beamsplitter repeats this process with the other pair of beams from the first polarization beamsplitter. The result is two net output currents which between them contain all the phase and amplitude information needed to define and control the polarization of the incoming signal. In addition to reducing sensitivity to the polarization state of the incoming signal, the use of polarization beamsplitters substantially improves optical efficiency, in comparison to prior art using amplitude beamsplitters.
REFERENCES:
patent: 3694656 (1972-09-01), Henning
patent: 4506388 (1985-03-01), Monerie et al.
Itek Corporation
Orsino Jr. Joseph A.
Rotella Robert F.
Wallach Michael H.
LandOfFree
Polarization matching mixer does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Polarization matching mixer, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Polarization matching mixer will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1639633