Abstract: A tunable liquid crystal switch is disclosed. An electronic controller provides an electronic drive scheme for achieving low intra-channel crosstalk of less than −40 dB using only electronic compensation. A cross-talk less than −50 dB is provided by combining coarse temperature turning and electronic compensation. This is acheived by designing the thickness of the liquid crystal device to cause a minimum to occur at a wavelength longer than a longest operating wavelength and at a temperature greater than a maximum operating temperature. This ensures that the liquid crystal device is tunable over all operating wavelengths and temperatures using electronic compensation.

Abstract: A method of and system for estimating the bit error rate of a channel in an optical communication system includes a method of and system for measuring the in-band cross-talk of the channel in a wavelength division multiplexed system. A single channel is selected from the plurality of channels in the optical communication system. The signal in this single channel is passed to a digital signal processor proportional to the time rate of change of a phase of an optical source generating the signal. The digital signal processor converts the filtered signal into the frequency domain, and a spectrum analyzer determines the features of the in-band cross-talk from the signal in the frequency domain. The features of the in-band cross-talk may be combined with other measured noise features, such as the power spectral density, to estimate BER.

Abstract: A tunable liquid crystal switch is disclosed. An electronic controller provides an electronic drive scheme for achieving low intra-channel crosstalk of less than −40 dB using only electronic compensation. A cross-talk less than −50 dB is provided by combining coarse temperature tuning and electronic compensation. This is acheived by designing the thickness of the liquid crystal device to cause a minimum to occur at a wavelength longer than a longest operating wavelength and at a temperature greater than a maximum operating temperature. This ensures that the liquid crystal device is tunable over all operating wavelengths and temperatures using electronic compensation.

Abstract: A tunable liquid crystal switch is disclosed. An electronic controller provides an electronic drive scheme for achieving low intra-channel crosstalk of less than −40 dB using only electronic compensation. A cross-talk less than −50 dB is provided by combining coarse temperature tuning and electronic compensation. This is acheived by designing the thickness of the liquid crystal device to cause a minimum to occur at a wavelength longer than a longest operating wavelength and at a temperature greater than a maximum operating temperature. This ensures that the liquid crystal device is tunable over all operating wavelengths and temperatures using electronic compensation.

Abstract: A tunable liquid crystal switch is disclosed. An electronic controller provides an electronic drive scheme for achieving low intra-channel cross-talk of less than −40 dB using only electronic compensation. A cross-talk less than −50 dB is provided by combining coarse temperature tuning and electronic compensation. This is acheived by designing the thickness of the liquid crystal device to cause a minimum to occur at a wavelength longer than a longest operating wavelength and at a temperature greater than a maximum operating temperature. This ensures that the liquid crystal device is tunable over all operating wavelengths and temperatures using electronic compensation.

Abstract: An optical device protection system provides dedicated and shared protection for a plurality of optical working devices which may include four-port optical working devices. The system includes an optical switch structure for routing an optical signal around an optical device when the optical device exhibits an error condition. A protection optical device performs a desired operation on the optical signal, wherein the optical switch structure directs the optical signal through the protection optical device. The use of liquid crystal switches allows the optical switch structure to sense an incorrect capacitance value associated with the liquid crystal switch. A control signal is then generated in response to the incorrect capacitance value. Thus, the optical device protection system provides flexibility and a low cost method for protecting complex optical devices.

Abstract: A system and method for controlling an electron beam in accordance with the present invention includes an electron gun, a cathode ray tube with a faceplate, a deflection drive, a pair of positioning electrodes, an electron beam controller, and a pair of capacitors. The electron gun generates an electron beam in the cathode ray tube which is deflected in a desired direction towards and between at least one pair of positioning electrodes formed on the inner surface of the faceplate. Each of the positioning electrodes generates a position signal which is capacitively coupled by the capacitors to the electron beam controller. The electron beam controller adjusts the deflection of the electron beam in response to the position signals. The capacitors comprise a pair of first and second capacitor plates which are separated by the cathode ray tube. The first capacitor plates are disposed on opposing sides of an inner surface of the cathode ray tube adjacent to the faceplate.