Abstract: A method for calibrating a laser transmitter includes (a) detecting an eye diagram of an output from the laser transmitter, (b) determining if the eye diagram is acceptable, (c) if the eye diagram is not acceptable, changing a value of a control signal in the laser transmitter, wherein the control signal sets an amplitude characteristic of a limiting amplifier coupled to a laser driver in the laser transmitter, and (d) repeating steps (a), (b), and (c) until the eye diagram is acceptable.

Abstract: A laser transmitter includes an input stage generating an input signal to a limiting amplifier, the limiting amplifier generating an input signal to a laser driver, and the laser driver generating an input signal to a light source. The limiting amplifier has a control terminal for receiving a control signal that sets an amplitude characteristic of the input signal to the laser driver. The amplitude characteristic may be a common-mode or a peak amplitude of the input signal to the laser driver.

Abstract: An integrated circuit cast on a single die having a plurality of receivers in a receiver region, a plurality of transmitters in a transmitter region, and a spatial separation region having a plurality of n-type and p-type subregions disposed on the single die to separate the transmitter region from the receiver region. The pn-junctions between the n-type and p-type subregions are reverse-biased thereby reducing or eliminating coupling of noise and crosstalk between the transmitter and receiver is reduced.

Abstract: An integrated circuit cast on a single die having a plurality of receivers in a receiver region, a plurality of transmitters in a transmitter region, and a spatial separation region having a plurality of n-type and p-type subregions disposed on the single die to separate the transmitter region from the receiver region. The pn-junctions between the n-type and p-type subregions are reverse-biased thereby reducing or eliminating coupling of noise and crosstalk between the transmitter and receiver is reduced.

Abstract: An optical receiver system includes an amplifier circuit and a compensation circuit. The amplifier circuit includes a light detector, and a transimpedance amplifier. The transimpedance amplifier produces an amplified signal. The compensation circuit includes at least one pole compensation stage that performs pole compensation on the amplified signal.

Abstract: A digital graphics connection such as a DVI connection uses an optical fiber for transmissions representing a clock signal and parallel pixel data channels. In one embodiment, a DVI cable includes a source-side connector containing active circuitry such as a multiplexer that interleaves pixel data and clock information and a driver circuit that controls a laser transmitting an optical signal on the optical fiber. The display connector can include a photodiode, a clock and data recovery circuit, and a demultiplexer that reconstructs the parallel electronic signals.

Abstract: An integrated circuit for providing burn-in current to a laser diode. The integrated circuit includes a laser driver having an output for connection to the laser diode. Burn-in circuitry is formed on the integrated circuit and generates a burn-in current. A switch is formed on the integrated circuit and couples the burn-in current to the laser diode in response to an enable signal.

Abstract: A method for calibrating a laser transmitter includes (a) detecting an eye diagram of an output from the laser transmitter, (b) determining if the eye diagram is acceptable, (c) if the eye diagram is not acceptable, changing a value of a control signal in the laser transmitter, wherein the control signal sets an amplitude characteristic of a limiting amplifier coupled to a laser driver in the laser transmitter, and (d) repeating steps (a), (b), and (c) until the eye diagram is acceptable.

Abstract: An optical receiver uses a clock data recovery block to improve the jitter and the power consumption of the optical receiver. The optical receiver includes a photodetector for receiving an optical signal and generating a corresponding current signal, a gain stage coupled to the photodetector for receiving the corresponding current signal and converting it to a corresponding voltage signal, and a clock data recovery circuit coupled to the gain stage for receiving the corresponding voltage signal, extracting clock information from the corresponding voltage signal, and regenerating the corresponding voltage signal to reduce jitter.

Abstract: A laser driver for generating drive waveforms that are suitable for driving a single VCSEL or an array of VCSELs. A digital controller is integrated into the laser driver and is utilized to initially program and selectively adjust during the operation of the driver one or more of the following VCSEL drive waveform parameters: (1) bias current, (2) modulation current, (3) negative peaking depth, and (4) negative peaking duration. The laser driver has an aging compensation mechanism for monitoring the age of the laser and for selectively adjusting the dc and ac parameters of the VCSEL drive waveform to compensate for the aging of the laser. The laser driver also has a temperature compensation mechanism for monitoring the temperature of the driver IC and selectively adjusting the dc and ac parameters of the VCSEL drive waveform to compensate for the changes in temperature.

Abstract: A communications system includes a transceiver and a host board. The transceiver includes an interrupt request terminal and a communication port. The host board includes an interrupt request line and a communication bus, wherein the interrupt request line is coupled to the interrupt request terminal to receive an interrupt request, and the communication bus is coupled to the communication port to receive data.

Abstract: A method for calibrating a laser transmitter includes (a) detecting an eye diagram of an output from the laser transmitter, (b) determining if the eye diagram is acceptable, (c) if the eye diagram is not acceptable, changing a value of a control signal in the laser transmitter, wherein the control signal sets an amplitude characteristic of a limiting amplifier coupled to a laser driver in the laser transmitter, and (d) repeating steps (a), (b), and (c) until the eye diagram is acceptable.

Abstract: An integrated circuit cast on a single die having a plurality of receivers in a receiver region, a plurality of transmitters in a transmitter region, and a spatial separation region having a plurality of n-type and p-type subregions disposed on the single die to separate the transmitter region from the receiver region. The pn-junctions between the n-type and p-type subregions are reverse-biased thereby reducing or eliminating coupling of noise and crosstalk between the transmitter and receiver is reduced.

Abstract: Disclosed are methods and apparatus for testing opto-electronic devices. Test data is shifted into a first boundary-scan cell. A test is then launched from the first boundary-scan cell by outputting the shifted test data to a signal generator. The signal generator, in turn, provides conditioned test data to an opto-electronic transmitter, in response to the shifted test data and at least one constraint for operating the opto-electronic transmitter. Finally, a response to the test is captured.

Abstract: Disclosed are methods and apparatus for testing opto-electronic devices. Test data is shifted into a first boundary-scan cell. A test is then launched from the first boundary-scan cell by outputting the shifted test data to a signal generator. The signal generator, in turn, provides conditioned test data to an opto-electronic transmitter, in response to the shifted test data and at least one constraint for operating the opto-electronic transmitter. Finally, a response to the test is captured.

Abstract: For each channel in a parallel channel optical array, a diffractive optical arrangement (DOA) includes an input region that is configured to pass a first portion of an input beam to an output region for data transmissions and to diffract and direct a second portion to a detection region for monitoring. The input region includes the diffractive features of a computer generated hologram (CGH) or a grating for diffracting. Alternatively, the input region is coupled to the CGH or grating. Moreover, the DOA includes at least one reflective region for redirecting the second portion. In one embodiment, the DOA includes a separate active surface for each channel of the array. Alternatively, the DOA has a singular active surface that is positioned to interact with all the channels. Optical power output from the second portion is monitored to generate feedback signals for adjusting the input current to each laser. Additionally, optical power output from sensed temperature is monitored to generate feedback signals.

Abstract: A laser driver for generating drive waveforms that are suitable for driving a single VCSEL or an array of VCSELs. A digital controller is integrated into the laser driver and is utilized to initially program and selectively adjust during the operation of the driver one or more of the following VCSEL drive waveform parameters: (1) bias current, (2) modulation current, (3) negative peaking depth, and (4) negative peaking duration. The laser driver has an aging compensation mechanism for monitoring the age of the laser and for selectively adjusting the dc and ac parameters of the VCSEL drive waveform to compensate for the aging of the laser. The laser driver also has a temperature compensation mechanism for monitoring the temperature of the driver IC and selectively adjusting the dc and ac parameters of the VCSEL drive waveform to compensate for the changes in temperature.

Abstract: For each channel in a parallel channel optical array, a diffractive optical arrangement (DOA) includes an input region that is configured to pass a first portion of an input beam to an output region for data transmissions and to diffract and direct a second portion to a detection region for monitoring. The input region includes the diffractive features of a computer generated hologram (CGH) or a grating for diffracting. Alternatively, the input region is coupled to the CGH or grating. Moreover, the DOA includes at least one reflective region for redirecting the second portion. In one embodiment, the DOA includes a separate active surface for each channel of the array. Alternatively, the DOA has a singular active surface that is positioned to interact with all the channels. Optical power output from the second portion is monitored to generate feedback signals for adjusting the input current to each laser. Additionally, optical power output from sensed temperature is monitored to generate feedback signals.

Abstract: The present invention is a signal detect (SD)/loss-of-signal (LOS) circuit that is able to discern between received Signal and Noise in Digital Amplitude Modulated transmission systems. A window detector, having a low and high voltage limit, receives an input signal. A low pass filter having an output connects to the window detector. A differential comparator compares the output of the low pass filter at a negative input and a threshold voltage signal to generate an output signal indicative of the average power of the input signal.