Jds Uniphase Corporation

Louis B Allard

John Martinho

Jonathan Paradis

Mike Trzecieski

Alex Tager

Clark Merchant

A polarization controller comprising means for generating linearly polarized light and at least one liquid crystal cell. A preferred embodiment of the invention comprises a linear polarizer and two liquid crystal cells. In the preferred embodiment, the polarization direction of the polarizer and the orientation of the fast axis of the first and second liquid crystal cells are oriented in a manner that allows the linearly polarized light provided by the polarizer to be transformed into any state of polarization at the output of the second liquid crystal cell. The present invention provides full coverage of the Poincar&#xe9; sphere.

Polarization controller

In order to calibrate an apparatus for measuring the polarization dependent loss of an optical device under test, a set of nominal polarization states of incident light are generated with a polarization generator. The incident light is then passed through a dot-product conserving polarization rotator at a first setting. A transmission characteristic is measured through a standard optical component with a known polarization dependent loss value for each polarization state. This step is repeated for a number of different settings of the polarization rotator. A polarization dependent loss value is calculated for the standard optical component based on the measured transmission characteristics at each polarization rotator setting. The calculated polarization dependent loss values are then processed to generate an aggregate error value. The aggregate error value is minimized by adjusting the values of the nominal polarization states to estimate the actual polarization states, which can then be used to calculate the polarization dependent loss of an optical device whose value is unknown.

Polarization dependent loss measurement in photonic devices

An electrooptic waveplate for changing the state of polarization of light passing therethrough is disclosed. The waveplate provides a substantially constant birefringence when the principle birefringent axes of the electrooptic waveplate are rotated. The waveplate is an electro-optical material having two principle orthogonal birefringent axes that are rotable when suitable voltages are applied. Two related different voltages are applied along sequential or contiguous regions along the length L of the electo-optical waveplate for providing a controllable and varying electric field along the length L, such that retardance of the waveplate of the length L remains substantially constant while the birefringent axes of the elecrooptic waveplate are rotated by varying the voltages. The two different voltages have a phase relationship or a phase and magnitude relationship therebetween.

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Ottawa, Canada

Louis B Allard