The FT-DV412xR family contains two photodetector devices, with optimized ultrafast photodiodes with up to 100 GHz bandwidth. Both photodetectors, the XPDV4120 (f3dB > 90 GHz) and XPDV4121R (f3dB >100 GHz), are designed with waveguide-integrated photodiodes and show an extremely flat frequency response in power and in phase. The on-chip integrated bias network with optimized RF design in particular, ensures undisturbed frequency response from DC to the 3 dB cut-off frequency and saves costs for internal bias-tees. The devices are especially developed for optimal RF performance revealing virtually no pulse response ringing.

Both photodetectors are characterized in the frequency domain by using a heterodyne technique. In the time domain, a femtosecond pulse source and a 65 GHz sampling oscilloscope are used to measure the pulse response.

The photodetector is designed to exhibit an optimized frequency response in both power and phase. It is ideally suited for OC-768/STM-256 long haul systems. The high power capability of up to 10 dBm allows for use of optical amplification at the detector input, and results in a high output voltage swing of up to 1V avoiding the need for electrical amplification. The photodetector is optimized for dual operations at 1310 nm and 1550 nm.

A waveguide integrated pin diode provides an excellent linearity, high responsivity and a superior flatness of the RF response. An integrated biasing guarantees a highly reliable component.

The photodetector contains a waveguide-integrated pin-photodiode (PD), designed to exhibit optimized high frequency performance in both, amplitude and phase. A linear response up to an optical input power of 10 dBm is a feature of these modules, enabling to drive subsequent decision circuits of communication systems directly. The pin-photodiode with on-chip integrated bias network in conjunction with a blocking capacitor for AC coupling is the best choice for 44 Gb/s applications.

The photodetector consists of a well-established, waveguide-integrated single photodiode chip, designed to exhibit an optimized frequency response in both power and phase. Due to experienced RF packaging, the pulse response shows almost no ringing. Our integrated on-chip spot size converter leads to a high responsivity and ensures reliability and robustness of the FT-DV. An advantage of the waveguide structure is the unsurpassed high-power behavior with linear response up to an optical input power of 10 dBm. For short pulses, an output voltage swing of more than 1 Vpp can be achieved without any degradation of the pulse response. FT-DVs contain a unique on-chip integrated bias network and ensure undisturbed frequency response from DC to the 3 dB cut-off frequency.