Ii-vi Delaware, Inc.

Finisar Corporation

Optium Australia Pty Limited

Glenn Wayne Baxter

Steven James Frisken

Luke Stewart

Vincent Choo

Nitesh Gulati

Yiwei Xu

Dmitri Abakoumov

Hao Zhou

Qihong Wu

Jonathan Plumridge

Cibby Pulikkaseril

Novelene Wang

Julian Armstrong

Described herein are embodiments of a diffractive optical element () such as a grism. In one embodiment, the diffractive optical element () includes an input surface () configured to receive an input optical signal (), a diffractive surface () adapted to spatially disperse the input optical beam () into a dispersed signal and an output surface () configured to output the dispersed signal from the diffractive optical element. The input surface () and the diffractive surface () are non-parallel and the diffractive surface () is formed in situ by a photolithographic technique.

Diffractive optical element

Diffractive optical element fabrication

A liquid crystal on silicon (LCOS) device includes a silicon substrate and a pair of electrodes including an upper and a lower electrode. The lower electrode is mounted to the silicon substrate and includes a two dimensional array of pixels extending in both a first and second dimension. LCOS device also includes a liquid crystal layer disposed between the upper and lower electrodes and configured to be driveable into a plurality of electrical states by drive signals provided to the pixels of the lower electrode. The pixels are rectangular in profile having longer sides in the first dimension than in the second dimension. Further, the two dimensional array includes a pixel pitch that is greater in the first dimension than in the second dimension.

WSS utilizing LCOS arrays comprising rectangular pixels

Described herein is a diffraction grating () for use in an optical system. The diffraction grating includes a substrate () and an array of elongate diffracting elements () arranged in a grating profile across the substrate. The grating profile imparts a predefined phase change to optical beams to at least partially correct the beams for optical aberrations present in the optical system.

Systems and methods of aberration correction in optical systems

Described herein is an optical phase modulator () including a liquid crystal element (), disposed between a pair of opposing electrodes () and (). The electrodes () are electrically driven for supplying an electric potential V across the liquid crystal element () to drive the liquid crystals within element () in a predetermined configuration. Electrode () includes a grid of individually drivable pixel regions (), at least some of which include a sub-wavelength grating structure that provides an anisotropic refractive index profile in orthogonal lateral dimensions, thereby creating an effective material form birefringence. Light incident through liquid crystal element () and onto electrode () is reflected and experiences a relative phase difference of 180&#xb0; between its constituent orthogonal polarization components, thereby rotating each polarization component into the orthogonal orientation upon reflection.

Polarization-independent LCOS device

Through its higher refractive index, a silicon grism can be used to reduce the Described herein are systems and methods for reducing optical aberrations in an optical system to decrease polarization dependent loss. Embodiments are provided particularly to define beam trajectories through an optical switching system which reduce off-axis aberrations. In one embodiment, a silicon grism is provided for reducing the curvature of the focal plane at an LCOS device in a wavelength selective switch (WSS) such that the separated polarization states converge at the LCOS at substantially the same point along the optical axis for all wavelengths. In this embodiment, an axial offset at the LCOS device will not produce large PDL at the coupling fibers. In another embodiment, a coupling lens having an arcuate focusing region is provided to address an offset in the optical beams, such that the separated polarization states couple symmetrically to respective output fibers.

Systems and methods for reducing off-axis optical aberrations in wavelength dispersed devices

Described herein are systems and methods of enhancing channel bandwidth in an optical system having a number of wavelength selective switching (WSS) devices. The method includes the steps of passing the optical signals through the WSS devices by: (i) spatially dispersing the wavelength channels of the optical signals; (ii) projecting the spatially dispersed channels onto corresponding predetermined regions of an optical manipulation matrix including a plurality of individually addressable manipulating elements; (iii) determining a modification function that specifies a state for each manipulating element within the predetermined region; and (iv) driving the elements of the corresponding regions at states specified by the function to selectively modify the channel band shape such that the received channel's bandwidth is substantially enhanced, and to spatially direct the wavelength channels to predetermined output ports of the WSS devices.

Optical wavelength selective switch calibration system

An optical coupling device including: at least a first input port for delivering an optical input signal beam that includes a plurality of wavelength channels; at least a first optical output port for receiving an optical output signal beam; a wavelength dispersion element for spatially separating the plurality of wavelength channels in the optical input signal beam to form a plurality of spatially separated wavelength channel beams; an optical coupling device for independently modifying the phase of each of the spatially separated wavelength channel beams such that, for at least one wavelength channel beam, a selected fraction of the light is coupled to the first output port and a fraction of the light is coupled away from the first output port.

Wavelength selective reconfigurable optical cross-connect

In an optical system including an optical input port for projecting an input optical signal onto an optical phased matrix array, an optical phased matrix array including a plurality of individually addressable pixels thereon, each said pixel being drivable within a prescribed range of levels, and an optical output port for collecting a predetermined fraction of said optical signal received from said optical phased matrix array; a method of compensating for phase distortions including the steps of: (a) determining a plurality of transfer functions relating said level of each said pixel to the phase variation each said pixel introduces to light from said input optical signal which is incident thereon; and (b) controlling the level of selected ones of said pixels in accordance with a corresponding transfer function such that said fractional signal received at said output port is modified in phase to substantially compensate for optical phase distortions arising from said optical phased matrix array.

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Hornsby Heights, Australia

Glenn Wayne Baxter