Abstract: A method and apparatus for controlling the attenuation level of a semiconductor VOA relative to an absolute temperature of the VOA without the use of a power monitor is provided. The method includes the step of providing a variable optical attenuator for attenuating the optical signal. The variable optical attenuator is instructed to maintain the desired attenuation level of the optical signal. The temperature of the variable optical attenuator is periodically sensed, and a required voltage level is determined to achieve the desired attenuation level based at least partially on the periodically sensed temperature of the VOA. The method can further include the step of increasing and decreasing a voltage to the VOA to achieve the required voltage level and thus the desired attenuation level.

Abstract: A method and apparatus for controlling the attenuation level of a semiconductor VOA relative to an absolute temperature of the VOA without the use of a power monitor is provided. The method includes the step of providing a variable optical attenuator for attenuating the optical signal. The variable optical attenuator is instructed to maintain the desired attenuation level of the optical signal. The temperature of the variable optical attenuator is periodically sensed, and a required voltage level is determined to achieve the desired attenuation level based at least partially on the periodically sensed temperature of the VOA. The method can further include the step of increasing and decreasing a voltage to the VOA to achieve the required voltage level and thus the desired attenuation level.

Abstract: A peak detector for use in a fiber optic receiver has a capacitor, an input amplifier driving the capacitor, and a feedback differential amplifier coupled between the capacitor and an input of the input amplifier. The input amplifier is a complementary buffer with unity gain modified to include an additional transistor on one rail that receives an inverter voltage generated by the differential amplifier. The inverter voltage equals the difference between twice the capacitor voltage and an input voltage applied to the peak detector. The input amplifier in a positive peak detector functions so that the capacitor voltage tracks the input voltage when it exceeds the inverter voltage, and equals the average of the input voltage and inverter voltage when the input voltage is less than the inverter voltage. A negative peak detector operates similarly but with opposite polarity. The peak detector also contains transistors used to reset the capacitor voltage upon assertion of a reset signal.

Abstract: A peak detector for use in a fiber optic receiver has a capacitor, an input amplifier driving the capacitor, and a feedback differential amplifier coupled between the capacitor and an input of the input amplifier. The input amplifier is a complementary buffer with unity gain modified to include an additional transistor on one rail that receives an inverter voltage generated by the differential amplifier. The inverter voltage equals the difference between twice the capacitor voltage and an input voltage applied to the peak detector. The input amplifier in a positive peak detector functions so that the capacitor voltage tracks the input voltage when it exceeds the inverter voltage, and equals the average of the input voltage and inverter voltage when the input voltage is less than the inverter voltage. A negative peak detector operates similarly but with opposite polarity. The peak detector also contains transistors used to reset the capacitor voltage upon assertion of a reset signal.