Oclaro (north America Inc.)

Avanex Corporation

Other

Ii-vi Incorporated

Haijun Yuan

Giovanni Barbarossa

Xuehua Wu

Christopher Lin

Ming Chu Li

Song Peng

Yongsheng Liu

Xingzhong Zhao

Younsheng Liu

An optical switch for performing high extinction ratio switching of an optical signal includes a beam polarizing element and one or more optical elements. The optical elements are configured to direct an optical signal along a first or second optical path based on the polarization state of the optical signal as it passes through the optical elements. The optical switch performs high extinction ratio switching of the optical signal by preventing unwanted optical energy from entering an output port by using an absorptive or reflective optical element or by directing the unwanted optical energy along a different optical path.

High extinction ratio liquid crystal optical switch

An optical device is configured to perform both switching and attenuation of an optical beam in response to a single control signal. The optical device includes a liquid-crystal-based beam-polarizing element having polarization-conditioning regions that are controlled using a common electrode. The first polarization-conditioning region conditions the polarization of the input beam in order to separate the input beam into a primary component and a residual component. The second and third polarization-conditioning regions change the polarization of the primary component and the residual component, respectively. The primary component is directed to an output port after it has been attenuated based on its polarization state. The residual component, after passing through the third polarization-conditioning region, has its intensity further reduced based on its polarization state.

Single control liquid crystal optical switch and attenuator

An optical device for a wavelength division multiplexing system has a telecentric lens system and a signal-processing optical element, where the signal-processing optical element performs switching, attenuation, or other optical signal processing for the optical device. The telecentric lens system acts as a self-compensating optical system to minimize sensitivity of the optical device to unwanted displacement of an input image from the optical axis of the optical device. The optical device may include multiple telecentric lens systems, in which case the optical device is also less sensitive to precise alignment between the telecentric lens systems.

Optical device with stable optical configuration

A fiber lens assembly is configured to optically couple an optical fiber to a signal processing device having free-space optical elements. The fiber lens assembly includes a diverging lens having a focal length that may be around 2 to 6 times the diameter of the optical fiber core. Sensitivity of the fiber lens assembly to angular misalignment and positional displacement is reduced by coupling the optical fiber to the signal processing device using a diverging lens rather than a collimating lens, and by configuring the diverging lens with a suitable focal length.

Fiber lens assembly for optical device

A liquid crystal optical performance monitor is described that employs a liquid crystal tunable filter for receiving a P-polarization beam and a rotated S-polarization beam from a C-polarizer. The rotated S-polarization beam from a birefringent crystal in C-polarizer propagates through a waveplate which rotates the polarization by 90 degrees, resulting in the rotated S-polarization beam having the same polarization orientation as the P-polarization beam. The liquid crystal tunable filter therefore receives just the P-polarization orientation. The C-polarizer and a small beam collimator are rotated so that the polarization orientation of the P-polarization beam and the rotated S-polarization beam matches the orientation of the LC inside the LC cavity of the LC tunable filter. In a first embodiment, the liquid crystal optical performance monitor is implemented with a photodiode. In a second embodiment, the liquid crystal optical performance monitor is implemented with a bi-cell photo diode.

Liquid crystal device and method for optical performance monitoring in fiber optic communication systems

A polarization controller includes: a liquid crystal cell; a mechanism for determining a compensation voltage; and a voltage driving circuit for applying the compensation voltage to the liquid crystal cell, where the application of the compensation voltage optimizes an extinction ratio of the liquid crystal cell. The controller controls the extinction ratio using an applied voltage to compensate for temperature changes, liquid crystal cell gap variations, and other errors of the liquid crystal cell. This controller is aimed at liquid crystal devices used in a wide ambient temperature range and is also useful to compensate for the fabrication errors of the liquid crystal switches.

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Pleasanton, CA, United States of America

Haijun Yuan