Andreas Beling

High-Saturation-Current Modified Uni-Traveling-Carrier Photodiode With Cliff Layer

We demonstrate two modified uni-traveling carrier photodiode (MUTC) structures that incorporate a charge or “cliff” layer to attain high-saturation-current. MUTC1 achieved responsivity of 0.82 A/W and 134 mA saturation current at -6-V and 20 GHz. The MUTC2 structure, which has higher doping density in the cliff layer and thinner absorption region, exhibited a higher saturation current of 144 mA (at -5-V) and an improved 3 dB bandwidth of 24 GHz; however, the responsivity was reduced to 0.69 A/W. For MUTC2, a high-saturation-current bandwidth product of 3456 GHz mA has been achieved. An intermodulation distortion figure of merit, IP3, > dBm at 20 GHz was observed for both MUTC structures.

High-power high-linearity flip-chip bonded modified uni-traveling carrier photodiode

We demonstrate a flip-chip bonded modified uni-traveling carrier (MUTC) photodiode with an RF output power of 0.75 W (28.8 dBm) at 15 GHz and OIP3 as high as 59 dBm. The photodiode has a responsivity of 0.7 A/W, 3-dB bandwidth > 15 GHz, and saturation photocurrent > 180 mA at 11 V reverse bias.

InP-based waveguide-integrated photodetector with 100-GHz bandwidth

A waveguide-integrated photodetector is presented, exhibiting a bandwidth of 100 GHz. The responsivity amounts to 0.66 A/W and the PDL is below 0.9 dB. The detector chip is designed to obtain a Bessel filter-shaped transfer characteristic when packaged in a module comprising a 1-mm connector.

Miniaturized waveguide-integrated p-i-n photodetector with 120-GHz bandwidth and high responsivity

A low-capacitance waveguide-integrated photodiode on InP with a minimized absorber length is presented. In order to maintain a high quantum efficiency, an optical matching layer exploiting mode beating effects is employed. Its optimization leads to a twofold enhanced external responsivity of 0.5 A/W at 1.55-/spl mu/m wavelength in accordance with simulation. The reduced p-n junction capacitance enables 3-dB bandwidths up to 120 GHz mainly limited due to carrier transit time effects.

Fully-integrated polarization-diversity coherent receiver module for 100G DP-QPSK

A new compact coherent receiver module comprising a micro-optic polarization beam splitter and two InP-based 90° hybrids with integrated photodiodes is characterized at 112 Gbit/s DP-QPSK. A penalty of only 1.3 dB in OSNR sensitivity at a BER of 10−3 compared to theory was obtained at C-band wavelengths.

High-Speed Miniaturized Photodiode and Parallel-Fed Traveling-Wave Photodetectors Based on InP

A periodic parallel-fed traveling-wave photodetector (TWPD) with monolithically integrated power splitter is presented. The device exhibits an impedance match to the 50-Omega environment as well as a velocity match between the optical and electrical signals and shows a 3-dB bandwidth up to 85 GHz. The electrical output power reaches +10 dBm at 10 GHz. The device is based on evanescently coupled low-capacitance waveguide-integrated p-i-n photodiodes (PDs) with optimized optical matching layer which reveal a bandwidth of 145 GHz when employed as a stand-alone photodetector

High-Power V-Band InGaAs/InP Photodiodes

InGaAs/InP-modified uni-traveling carrier photodiodes with cliff layer were designed and fabricated for V-band (50-75 GHz) applications. The devices were flip-chip bonded on AlN submounts for efficient heat dissipation. A high-impedance transmission line was designed to compensate for the parasitic capacitance and enhance the bandwidth. Devices with 3-dB bandwidths of 50 and 65 GHz demonstrated high-output RF power of 20.3 and 15.9 dBm, respectively.

Measurement and Modeling of a High-Linearity Modified Uni-Traveling Carrier Photodiode

The third-order intermodulation distortions of an InGaAs-InP charge compensated modified uni-traveling carrier photodiode (PD) are characterized using a two-tone setup. At 310-MHz modulation frequency, the third-order local intercept point (IP3) reaches 52 dBm and remains above 35 dBm up to 21GHz. Based on experimental results for the dependence of responsivity and PD capacitance on bias voltage and photocurrent, we use a simple equivalent circuit model to simulate the frequency characteristics of the intermodulation distortions.

Epitaxially-grown Ge/Si avalanche photodiodes for 1.3µm light detection

We designed and fabricated Ge/Si avalanche photodiodes grown on silicon substrates. The mesa-type photodiodes exhibit a responsivity at 1310nm of 0.54A/W, a breakdown voltage thermal coefficient of 0.05%/°C, a 3dBbandwidth of 10GHz. The gain-bandwidth product was measured as 153GHz. The effective k value extracted from the excess noise factor was 0.1.

Characterizing and Modeling Nonlinear Intermodulation Distortions in Modified Uni-Traveling Carrier Photodiodes

We present a physics-based model for nonlinear analysis of InGaAs/InP modified uni-traveling carrier (MUTC) photodiodes. At low frequencies (<;3 GHz), the Franz-Keldysh effect has been identified as the primary nonlinear mechanism in these MUTC photodiodes. The output third-order intercept point (OIP3) is used as a figure of merit for characterizing the nonlinear intermodulation distortion. The OIP3 behavior of the photodiode simulated using this model agrees well with measurements.