National Research Council of Canada

Chris Barnard

Neil Teitelbaum

Jacek Chrostowski

In an optical fibre system, an optical fibre is monitored to determine if a transmitted signal is being received at a receiving end. A bi-modal optical switch located between the laser transmitter and receiver operates in a first transmitting mode to allow a transmitted signal to pass through and in a second reflecting mode to reflect back the transmitted signal to the transmitting end. A monitor at the transmitting end monitors the fibre for the absence or presence of the reflected signal. The switch can be used to remotely monitor the receiver in an optical fibre link, to control handshaking between two computers, to remove idle sections from an optical fibre communications network, and to control the reflectance of a laser mirror.

Polarization independent transmissive/reflective optical switch

A frequency dependent optical isolator is provided which allows two signals transmitted on a single optical fiber to be isolated in dependence upon their frequencies. A signal having a frequency f1 propagates through the isolator in one direction from a first input/output port to a second input/output port and is prevented from propagating in the reverse direction. A signal having a frequency f2 propagates through the isolator from the second input port to the first input port and is prevented from propagating in the reverse direction. After either of the signals propagates through the isolator from one input/output port to the other, the isolator prevents the respective signal from traveling backwards in a reverse direction through the isolator. The frequency dependent isolator may be used with an amplifier or may amplify one or more of the signals propagating through.

Growing community of inventors

Orleans, Canada

Chris Barnard