MINI SIZE VOA

OVERVIEW

The Sercalo VX series are miniature opto-mechanical variable optical attenuators (VOA) for fiber optic communication systems and submodules. The non-latching attenuator allows for the continuous adjustment of the attenuation with a 0 – 5 V control voltage. The highly reliable attenuation mechanism is based on a micromechanical shutter and features below 20 ms response time and below 1.5 dB insertion loss. The VOA is available in single and dual variants.

The plastic package is one of the smallest in the industry. It is optimized for low cost production while maintaining high reliability comparable to a solid state device. The component is designed to meet Telcordia 1221 quality standards.

DESCRIPTION

The Sercalo VX variable optical attenuators are composed of an optical subsystem and an electrical driver interface. The optical attenuation is set by a silicon MEMS chip, on which a mirror can be moved in and out of the optical path by electrostatic actuation.

The internal driver interface converts the applied 5 V supply into a negative bias voltage and a positive high voltage. The positive voltage powers an operational amplifier. The attenuation is set by a 0-5 V input signal. This input signal is connected to the non inverting input of the operational amplifier which drives the electrostatic actuator of the MEMS variable optical attenuator (Figure 9). This high voltage design of the MEMS chip results a fast, robust and vibration insensitive attenuator.

The VX attenuators are available in single channel and dual channel variants. The standard VX attenuator achieves minimum insertion loss at 0 V input voltage. When power is removed the insertion loss is roughly 0.5 dB higher than the minimum insertion loss (at 0 V when power is on).