The Optoelectronics Division offers four Special Tests for high-speed optoelectronic frequency response.

• Optical modulation response transfer standard ─ An optical modulation response transfer standard consists of a photodiode and a microwave power meter and is calibrated as one unit. This type of transfer standard can be used to characterize the scalar modulation response of optoelectronic modulators and directly modulated lasers with very low uncertainty. This type of calibration typically has an uncertainty of 0.06 dB, which is considerably lower than most microwave measurements. The frequency range of this measurement is essentially limited by the power sensor, but can be 110 GHz or more. Phase-locked loop frequency control is available between 300 kHz and 1 GHz to achieve ultra-fine frequency resolution.
• Optical receiver frequency response magnitude ─ Calibrated optical receivers, typically photodiodes, are useful for testing many different types of optoelectronic components, including modulators, directly modulated lasers, and other optical receivers. The optoelectronics Division uses a heterodyne method to measure the (scalar) frequency response of receivers in a way that is traceable to fundamental microwave power standards. Results are reported as the response of the receiver when it is connected to an ideal 50 Ohm load using corrections for the impedance mismatch of the receiver an dpower meter.
• Optical receiver vector frequency response ─ Vector frequency response measurements are essential when phase response or time-domain properties are needed. This special test reports the magnitude and phase response of a high-speed photodiode in 0.2 GHz increments from 0.2 GHz to 110 GHz at a 1.00 mm (male) coaxial output connector. The photodiode can be de-embedded from a 1.00 mm adapter at an addition charge.
• Reference Receiver (Optical Oscilloscope) Vector Frequency Response ─ Oscilloscopes used for testing optical eye-patterns are specified in standards (such as SONET, SDH, Gigabit Ethernet, and Fibre Channel) to follow a 4 th-order Bessel-Thompson impulse response. Oscilloscopes used for testing otyher optical waveforms should have a high bandwidth and be free from aberrations. This service uses an optical impulse, along with corrections for jitter and timebase distortion, to calibrate the impulse response of oscilloscopes with a fiber-optic input.

Please contact Paul Hale or visit our High-Speed Measurements Project Web site for additional technical information.