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15 February 2001

Variable optic attenuator

This variable optic attenuator (VOA) chip incorporates a continuously adjustable element that can interrupt a light beam, thereby adjusting power level. It can also integrate with a dense wavelength division multiplexer for power equalization of individual wavelengths. The chip's design allows it to package with a customer's fiber elements and control electronics to form a VOA module. A MEMS actuator couples with an opaque attenuation vane to provide precise and stable attenuation settings. The VOA can couple with drive electronics to provide active feedback in continuous operation or in a "set and forget" latching mode in which no power flows between reconfigurations.

The MEMS actuator operates with 0–5 VDC input and sets the vane position within 20 milliseconds. The attenuation vane will provide up to 60 decibels of attenuation with single-mode fiber and has an optically engineered surface to limit back reflection to less than 50 decibels.