p-i-n /f.e.t. hybrid optical receiver for longer-wavelength optical communication systems

Low-noise receivers for fiber-optic microwave signal transmission

“…The design uses a shunt inductive element (either a shorted or open transmission line of appropriate length or an inductor) to resonate with the FET and photodiode capacitance, and hence this will be called a resonant front end. This preamplifier topology results in high current gain near resonance and thus minimizes the effect of the drain-source noise generator which is the principle sensitivity limitation of video receiver preamplifiers [17]. This type of front end should have good dynamic range since the input is a dc short and thus the average level of the optical input power does not result in either shift of the circuit bias levels or integrating action at the gate of the FET.…”

Optical receivers for lightwave communication systems

“…From the above expressions, it can be deduced that the p-i-n FET hybrid [27]- [30] offers a better sensitivity than other forms of p-i-n-photodiode receiver. A good sensitivity at higher bit rates requires a low input capacitance C: hybrid integration minimizes contributions from packages, and the sum of the capacitances of the p-i-n, FET, and the bias resistor R can be made less than 0.5 pF.…”

“…This section describes the design and performance of hybrid circuits for operation at up to 1.2 Gbit/s. Longer wavelength operation was provided first at 1.24 pm [27], then at 1.3 and 1.5 pm [28], using mesa-geometry InGaAs p-i-n photodiodes prepared from VPE-grown material. A substrate-entry p-i-n/fiber subassembly was then developed to minimize junction capacitance.…”

Very low reach-through voltage, high performance AlxGa1−x Sb p-i-n photodiodes for 1.3-μm fiber optical systems

“…The Alx Gal _ x Sb alloy system is closely lattice matched to GaSb substrates for x<0. 20 and can be perfectly matched by the addition of a small percentage of As. It may offer some advantges over InGaAsP/lnP for detectors in the 1.3-1.6-,um region, including a GaSb substrate with lower etch-pit density (-10 3 /cm 2 ) and at a lower cost than InP substrates.…”