University of Ottawa

Northern Telecom Limited

Mohsen Kavehrad

Gang Yun

Farideh Khaleghi

Hyung B Kim

Jinghui Li

Mansour I Irshid

Bidirectional WDM transmission at 2.5 Gb/s using a bidirectional erbium-doped fiber amplifier (EDFA) is demonstrated over a distance of 300 km. A symmetrical EDFA configuration with a frequency tunable reflection attenuator is used as a bidirectional amplifier. Experimental results show that the allowable gain of the EDFA can be increased significantly while the associated bit error rate BER penalty remains negligible.

Bidirectional optical amplifier

In N.times.N optical couplers, such as are used in local area networks and backplanes of telecommunications and computer equipment, which use BRAGG volume diffraction means to couple light beams between the inputs and outputs, the number of gratings is reduced by means of so-called 'grating degeneration' one grating can be shared by at least two wave pairs at the same time. In order to achieve this reduction, the directions of light waves in the dielectric slab (or the lateral positions of fibre ends) are suitable arranged. In other embodiments, a reduced number of gratings is achieved by using a 'sandwiched' structure which uses multi-layered dielectric slabs. Both embodiments may be combined in the one coupler.

Optical interconnection device

An optical receiver includes a photodiode having a surface area of suitable dimensions to permit reception of a signal at a high bit rate. Also, the optical receiver includes an optical taper having a head and a tail. The head is of greater diameter than the tail, and co-axial with the tail. The tail is aligned with the photodiode.

Optical taper for increasing the effective area of a photodiode in

An optical homodyne differential phase shift keying (DPSK) receiver for receiving and demodulating optical input signals, is provided with a power splitter for splitting the input signal into first and second signals, a delay is applied to the second signal, an optical amplifier optically amplifies the delayed second signal, and a balanced noise reduction circuit combines the first signal and the delayed amplified second signal to produce a demodulated output signal.

Growing community of inventors

Cumberland, Canada

Mohsen Kavehrad