BIDIRECTIONAL OPTICAL COUPLER Russian patent published in 2008 - IPC H04B10/00 

FIELD: electric coupling.

SUBSTANCE: can be used within bidirectional optical coupling systems. Bidirectional optical coupler contains first and second transmitter-receiver signal centres, every of which is equipped with transmitter-receiver optical system including receiving plot with at least two collecting lenses and on the opposite side with concatenated along each collecting lens optical axis as follows: focusing objective lens, deflecting mirror coupled with respective collecting lens and coupling signal transmitter or coupling signal receiver, position-sensitive photodetector or laser. Coupling signal transmitter and coupling signal receiver are designed as light guide ends of diameter d and numerical aperture NA. Reflecting surface of deflecting mirror is coated with dichroic surface to provide reflected transmission of wave length λ₁ and advanced transmission of wave length λ₂ Coupling signal transmitter and receiver provide performance at wave length λ₁. Laser and position-sensitive photodetector provide performance at wave length λ₂. Laser of each transmitter-receiver signal centre is coupled with position-sensitive photodetector of counter transmitter-receiver signal centre, while each position-sensitive photodetector is electrically coupled with average power controller of coupling signal transmission of given transmitter-receiver signal centre. Receiving plot is fixed with supporting arm which from its side is connected to transmitter-receiver signal centre base with flat elastic plate, yet from the opposite side supporting arm is furnished with rests set against two transversely-spaced linear devices (actuators), supported by a transmitter-receiver signal centre base. Focusing objective lens consists of negative and positive lenses. Positive lens is coupled with receiving plot by fastener made of material with linear thermal expansion coefficient α₁. Negative lens is coupled with receiving plot by fastener made of material with linear thermal expansion coefficient α₂. Laser and position-sensitive photodetector are coupled with positive and negative lenses. Light guide ends are coupled with receiving plot by fastener made of material with linear thermal expansion coefficient α₂. Specified linear thermal expansion coefficients of fasteners are related by ratio as follows: , where: L - distance between collecting lens and coupled light guide end; F3 - positive lens focus of focusing objective lens; ΔT - permissible range of operating temperature.

EFFECT: improved performance of bidirectional optical coupler.

8 dwg