LC for Telecom

Defining New Directions

Laser Attenuator (LA)
	Liquid Crystals have a variety of other Electro-Optic uses. Shown to the left is a laser attenuator with optical feedback designed for high end commercial laser jet printing engines. This application required fast response time, wide operating temperature range, high incident power handling, and low reflectivity.

Variable Optical Attenuator (VOA)
	Shown to the left is a device used for variable optical attenuation for telecommunications applications. It is a 32 channel device which has 35dB attenuation range, the insertion loss is <-.29dB. It is designed to operate in the C and L bands.

Optical Cross Connects (OXCs)
	Optical Cross connects or switches of high dynamic range can easily be constructed with liquid crystal technology. Shown to the left is a single channel optical cross connect. This device has a fast response time (<20mS), large dynamic range (>40dB), and wide operating range (-10 to +85). This device can be configured to operate at any wavelength.

Optical Add Drop Module (OADM)

Optical Add Drop Modules (OADMs),or Reconfigurable Optical Add Drop Modules (ROADMs),are required when information or wavelengths are required to be added too or removed from a data stream on the internet. These configurations can be easily accomplished with liquid crystal technology with the added advantage of channel equalization due to the analog nature of liquid crystals. Shown to the left is a 100 channel device used in a OADM application.

Polarization Control (PC)

Liquid crystals are inherently, variable waveplates. A typical retardence curve for our devices is shown to the left. For telecommunications applications, Polarization Mode Dispersion (PMD) is a prominent problem in Ultra Long Haul and Long Haul Fiberoptic applications where existing standard fiber is in place. A single channel or multi channel device can be easily constructed to mate with a single fiber or bundle of fibers or wavelengths to reorient the polarization state such that it is preserved and signal degradation is minimized.

Dynamic Gain Equalizer (DGE)
	Shown to the left is an array of DGEs in process just prior to the algnment coating step coating. These units are 32 channel, reflective gold devices. The inter-channel spacing is 2.5um, with a channel width of 100um. This device is designed for C band (1528 - 1561nm) operation.