2019 Microwave photonics and high-speed photodetectors

High-Speed Photodetectors (Invited talk)
Andreas Beling
ECE Department, University of Virginia, Charlottesville, VA 22904, USA
e-mail: andreas@virginia.edu

ABSTRACT
This talk will review advances in photodetectors for high-speed applications with focus on analog systems. Recent results from flip-chip bonded modified uni-traveling carrier photodiodes and high-power photodiode arrays on silicon will be discussed.
Keywords: photodiode, photodetector

High-Speed Photodetectors


Full-Duplex Analog Radio-over-Fiber System based on an Integrated Transceiver with a Silicon Microring Modulator and a Transfer-Printed III-V Photodetector Student Paper
Zhenzhou Tang1,2,3, Jing Zhang2,3, Shilong Pan1, Gunther Roelkens2,3, Dries Van Thourhout2,3
1 Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, China
2Ghent University-imec, Technologiepark 126, 9052, Ghent, Belgium
3 Center for Nano- and Biophotonics, Ghent University, Belgium
e-mail: zhenzhou.tang@ugent.be, tangzhzh@nuaa.edu.cn

ABSTRACT
A full-duplex analog radio-over-fiber (RoF) system based on an integrated transceiver is proposed. The transceiver incorporates a C-band silicon microring modulator for the electrical-to-optical (E-O) conversion of the downstream signal and an O-band III-V photodetector (PD) is transfer printed onto the same chip for the optical-to-electrical (O-E) conversion of the upstream signal. With the integrated transceiver, a proof-of-concept experiment is carried out. An error vector magnitude (EVM) less than 6 % is achieved in the X-band for a 1-Gbps 16QAM-modulated signal transmitted through 5-km single mode fiber.
Keywords: radio transceivers, microwave photonics, silicon photonics, photodetector.

Full-Duplex Analog Radio-over-Fiber System based on an Integrated Transceiver with a Silicon Microring Modulator and a Transfer-Printed III-V Photodetector


Photonic Integrated Microwave Oscillator Based on Silicon Nitride Soliton Microcomb (Student Paper)
Junqiu Liu1, Jijun He1, Erwan Lucas1, Arslan S. Raja1, Rui Ning Wang1, Maxim Karpov1,
Hairun Guo1, Romain Bouchand1, and Tobias J. Kippenberg1
1E´cole Polytechnique Fe´de´rale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
e-mail: junqiu.liu@epfl.ch, tobias.kippenberg@epfl.ch

ABSTRACT
Soliton microcomb devices based on integrated waveguides are miniaturized optical frequency combs, which are ideal for portable applications for timing, spectroscopy and metrology. A particularly promising application is to build soliton-microcomb-based photonic integrated microwave oscillators. Yet, so far, soliton microcombs at microwave repetition rate have not been reported on integrated material platform, such as silicon nitride (Si3N4), mainly due to high optical losses in waveguides caused by the fabrication process. Here, by improving the photonic Damascene reflow process to fabricate integrated Si3N4 microresonators with quality factor exceeding 22  106, we demonstrate, not only for the first time but also with an ultralow power of 35 mW, the single
soliton formation at 19.6 GHz repetition rate, in the microwave K-band. We characterize the phase noise of the soliton repetition rate, and reveal that the main issue limiting the phase noise performance is the chip input coupling. Furthermore, we demonstrate single soliton at a repetition rate as low as 9.77 GHz. Our results pave the way to low-noise, cost-effective, small-footprint, soliton-microcomb-based integrated microwave oscillator using low-loss Si3N4 waveguides, promising for chip-based communication, radar, high-frequency arbitrary waveform generation and spectroscopy.
Keywords: Microwave photonics, frequency comb, integrated photonics, microresonator, silicon nitride, nonlinear
optics.

Photonic Integrated Microwave Oscillator Based on Silicon Nitride Soliton Microcomb


EAM-based Microwave Mixer Implemented in Silicon Photonics (Student Paper)
Kasper Van Gasse1,2, Jochem Verbist1,2,3, Haolin Li3, Guy Torfs3, Johan Bauwelinck3, Gunther Roelkens1,2
1 Ghent University-imec, Technologiepark 15, 9052 Ghent – Belgium
2 Center for Nano- and Biophotonics, Ghent University, Belgium
3IDLab, Ghent University–Imec, Technologiepark 15, 9052 Ghent – Belgium
e-mail: kasper.vangasse @ugent.be

ABSTRACT
Analogue Radio-over-Fiber (ARoF) could play an enabling role in future small-cell Radio Access Networks (RANs). The use of high-frequency carriers in 5G requires wide-band and flexible frequency converter circuits. The use of ARoF allows performing the frequency conversion in the optical domain using wide-band and flexible microwave photonic up-conversion. A lot of research has been dedicated to the development of microwave photonic mixers using LiNbO3 MZMs with promising results. However, using discrete bulky components is not a scalable solution and could be difficult to use in small-cell Radio Access Networks. In this work we present a silicon photonic up-converter and transmitter circuit. The photonic integrated circuit consists of two high-bandwidth waveguide-coupled EAMs in a MZI structure. One EAM is driven by the data on an IF carrier while the other EAM is driven by a high frequency LO. We present first simulation results of the structure and compare these results to an alternative mixer topology. The fabricated EAM-MZI mixer is then fully characterized and used to up-convert 16-QAM and 64-QAM data on a 1.5-3.5 GHz IF to 26-28 GHz carrier frequencies and transmit it over 2 km of single mode fiber.
Keywords: Silicon photonics, Radio-over-fiber, Microwave photonics

EAM-based Microwave Mixer Implemented in Silicon Photonics


1310 nm quantum dot waveguide avalanche photodiode heterogeneously integrated on silicon
Bassem Tossoun, Géza Kurczveil, Chong Zhang, Antoine Descos, Xiaoge Zeng, Zhihong Huang, Di Liang, Raymond G. Beausoleil
Hewlett Packard Labs, Hewlett Packard Enterprise, 1501 Page Mill Road, Palo Alto, California 94304, USA
e-mail: bassem.tossoun@hpe.com

ABSTRACT
We demonstrate quantum dot (QD) waveguide avalanche photodiodes (APDs) on silicon at 1310 nm with a record high gain-bandwidth product of 240 GHz. A 3-dB bandwidth as high as 15 GHz and gain as high as ~45 were achieved. Open eye diagrams up to 12.5 Gb/s were taken and a sensitivity of -11 dB were demonstrated for the first time for any QD APD on silicon. Temperature studies were also made on these APDs, exhibiting high performance up to 60 C, and showing that these APDs can be practically used in an uncooled, WDM system on a silicon photonic platform.
Keywords: optoelectronics, avalanche photodiodes, silicon photonics, quantum dots, optical interconnects.

1310 nm quantum dot waveguide avalanche photodiode heterogeneously integrated on silicon