Patent ID: 7917041
Filing Date: 2011-03-29
Classification: G02F,H04B

Abstract:
1. A variable optical attenuator system for use within an optoelectronic device, comprising: a voltage multiplier circuit having an input node coupled to a microcontroller of an optoelectronic device and an output node coupled to a first terminal of a first transistor, wherein the voltage multiplier circuit multiplies a first control signal received from the microcontroller and provides the resulting multiplied control signal to the first terminal of the first transistor; the first transistor having the first terminal coupled to the output node of the voltage multiplier circuit, a second terminal coupled to the microcontroller, and a third terminal coupled to a polarization rotator, wherein the first transistor modulates the multiplied control signal with a second control signal received from the microcontroller at the second terminal and provides the resulting modulated control signal to the polarization rotator; and the polarization rotator disposed within a transmitter optical subassembly of the optoelectronic device and positioned along the emission axis of a corresponding optical light source, wherein the application of the modulated control signal to the polarization rotator alters the amount of polarization rotation applied to an optical data signal emitted by the optical light source, the optical data signal having a first polarization at the input of the polarization rotator; wherein the transmitter optical subassembly includes an exit polarizer positioned along the emission axis of the optical light source following the polarization rotator and having a second polarization such that altering the polarization rotation of the polarization rotator varies the attenuation of the optical data signal.