Allied Telesis, Inc.

Allied Telesyn International Corporation

Microalign Technologies, Inc.

Nikolai Fedyakin

Leonid Velikov

Shinkyo Kaku

Igor Gurevich

Victor Faibishenko

The optical signal multiplexer/demultiplexer of the invention is characterized by incorporating a bidirectional optical transceiver which is capable of using individual channels working in a transmitting and receiving modes simultaneously. The device consists of a number of optical prisms combined into a single module and provided with appropriate dichroic mirrors and interferrometric filters located on the outer surfaces of the prisms. According to one embodiment of the invention, the module consists of two sequentially arranged parallelogram prisms, a single-channel signal input/output unit with an optical collimator/focusator on one side of the prism module and a two-channel signal output/input unit with a respective optical collimator/focusator on the other side of the prism module. The first prism, which is located on the single-channel side has a first antireflective coating transparent to all input/output signals (&#x3bb;, &#x3bb;, &#x3bb;) and a second coating located on the two-channel side of the first prism that reflects one optical signal (&#x3bb;) and passes the remaining two optical signals (&#x3bb;and &#x3bb;). Thus, the input/output signals of several different wavelengths can be multiplexed/demultiplexed while passing in a multi-bounce zigzag expanded beam light paths in various combinations of signal-propagation directions. A pair of prism modules described above may be built-into a section of the main signal transmission/reception line and the output side of each prism module may be connected to a respective bidirectional optical signal transceiver.

Bidirectional optical signal multiplexer/demultiplexer

The optical module of the invention for high-speed bidirectional transceiver consists of a signal receiving unit, a signal transmitting unit, a common receiving-transmitting optical fiber, and a fiber coupling unit. The laser diode and the photodiode are arranged parallel to each other in closely located recesses of the module housing. Such an arrangement makes it possible to shorten distances for guiding lead wires from the terminals of the PC board to the respective terminals of the transmitting and receiving diodes. The laser diode emits a first transmitting laser beam that passes through a microobjective that collimates the beam and directs into onto a full-reflection mirror located inside the module housing. The full-reflection mirror reflects the first transmitting beam at an angle of 90&#xb0; and transmits it to the end face of an optical fiber through an optical fiber collimator that centers the beam with the fiber core. The module is provided with a second mirror, which is fully transparent to the aforementioned first transmitting beam, but is fully reflective to a second transmitting beam that may propagate in a direction opposite to the first transmitting beam on a different wavelength. Alignment of the optical components is facilitated due to the fact that it is carried out with diffractionally limited and collimated beams.

Optical module for high-speed bidirectional transceiver

Growing community of inventors

Mountain View, CA, United States of America

Nikolai Fedyakin