Abstract: A method of controlling the operating parameters of an optical modulator, without using a dither signal, is provided. Past operating parameters are compared to present operating parameters using a quality of modulation signal obtained by cross-correlating the data modulation signal used to drive the optical modulator with the modulated optical signal output from the optical modulator. The quality of modulation signal is used to optimize the operating parameters (e.g., bias point) of the optical modulator, or other operating parameters of the arrangement, such as the modulator drive level, timing alignment, etc.

Abstract: The invention relates to RF termination for reducing electrical signal reflections at the end of transmission line electrodes on an electro-optical (EO) optical modulator. The disclosed termination incorporates a RF tap which permits the monitoring of the RF power and reflection conditions at the EO modulator. The integrated termination/tap can also be integrated with detection circuitry, such as RF diodes and passive components, giving improved performance, lower cost manufacturability as well as a more compact and efficient package.

Abstract: A method of controlling the operating parameters of an optical modulator, without using a dither signal, is provided. Past operating parameters are compared to present operating parameters using a quality of modulation signal obtained by cross-correlating the data modulation signal used to drive the optical modulator with the modulated optical signal output from the optical modulator. The quality of modulation signal is used to optimize the operating parameters (e.g., bias point) of the optical modulator, or other operating parameters of the arrangement, such as the modulator drive level, timing alignment, etc.

Abstract: The invention relates to RF termination for reducing electrical signal reflections at the end of transmission line electrodes on an electro-optical (EO) optical modulator. The disclosed termination incorporates a RF tap which permits the monitoring of the RF power and reflection conditions at the EO modulator. The integrated termination/tap can also be integrated with detection circuitry, such as RF diodes and passive components, giving improved performance, lower cost manufacturability as well as a more compact and efficient package.

Abstract: A sine wave locked in phase and frequency to a carrier having a high second harmonic content, carrying information on the magnitude of a parameter, is applied to an open loop operational amplifier which provides a trapezoidal waveform to a high speed, differential transistor pair which provides a pair of squarewave signals whose duty cycles are regulated by varying the threshold at which the differential pair switches. The squarewaves may be used as a second-harmonic-free demodualting signal. The fundamental premise is that if the amplitude levels of the squarewave levels of the squarewave are known to a high degree of accuracy, and they are equal in the positive and negative directions, then the average value is zero only for a 50% duty cycle. A current regulator generates a selected current to a constant value with a high gain amplifier. This current is switched from one side to the other of the differential pair by the trapezoidal waveform.