High-responsivity InAs quantum well photo-FET integrated on Si substrates for extended-range short-wave infrared photodetector applications

Low-intensity light detection necessitates high-responsivity photodetectors.To achieve this,we report In_(0.53)Ga_(0.47)As∕In As∕In_(0.53)Ga_(0.47)As quantum well(InAs QW)photo-field-effect-transistors(photo-FETs)integrated on a Si substrate using direct wafer bonding.Structure of the In As QW channel was carefully designed to achieve higher effective mobility and a narrower bandgap compared with a bulk In_(0.53)Ga_(0.47)As,while suppressing the generation of defects due to lattice relaxations.High-performance 2.6 nm In As QW photo-FETs were successfully demonstrated with a high on/off ratio of 10~5 and a high effective mobility of 2370 cm^(2)∕(V·s).The outstanding transport characteristics in the InAs QW channel result in an optical responsivity 1.8 times greater than InGaAs photo-FETs and the fast rising/falling times.Further,we experimentally confirmed that the InAs QW photo-FET can detect light in the short-wavelength infrared(SWIR;1.0–2.5μm)near 2μm thanks to bandgap engineering through In As QW structures.Our result suggests that the InAs QW photo-FET is promising for high-responsivity and extended-range SWIR photodetector applications.

Large-signal SPICE model for depletion-type silicon ring modulators

We present an accurate, easy-to-use large-signal SPICE circuit model for depletion-type silicon ring modulators(Si RMs). Our model includes both the electrical and optical characteristics of the Si RM and consists of circuit elements whose values change depending on modulation voltages. The accuracy of our model is confirmed by comparing the SPICE simulation results of 25 Gb/s non-return-to-zero(NRZ) modulation with the measurement. The model is used for performance optimization of monolithically integrated Si photonic NRZ and pulse-amplitudemodulation 4 transmitters in the standard SPICE circuit design environment.

A Novel Technique of Measuring SOA Differential Carrier Lifetime and a -Factor Using SOA Optical Modulation Response

We demonstrate a new technique of measuring differential carrier lifetime and linewidth enhancement factor in a semiconductor optical amplifier. In our method, the optical responses and fiber transfer functions of a self-gain modulated SOA are measured and, from these, values of carrier lifetimes and linewidth enhancement factors are determined for various SOA input optical powers.

Silicon electronic-photonic integrated 25 Gb/s ring modulator transmitter with a built-in temperature controller

We demonstrate a silicon electronic–photonic integrated 25 Gb/s nonreturn-to-zero transmitter that includes driver circuits,depletion-type Si ring modulator,Ge photodetector,temperature sensor,on-chip heater,and temperature controller,all monolithically integrated on a 0.25μm photonic BiCMOS technology platform.The integrated transmitter successfully provides stable and optimal 25 Gb/s modulation characteristics against external temperature fluctuation.

Influence of dynamic power dissipation on Si MRM modulation characteristics

We experimentally observe that Si micro-ring modulator（MRM） modulation characteristics are strongly influenced by the modulation data rate and the data pattern and determine this influence is due to the temperature increase caused by dynamic power dissipation within the Si MRM device. We also quantitatively determine the amount of Si MRM resonance wavelength shift due to different modulation data rates, data patterns, and modulation voltages. Our results should be of great help for achieving reliable and optimal modulation characteristics for Si MRMs.