28 Gb/s direct modulation heterogeneously integrated C-band InP/SOI DFB laser

We demonstrate direct modulation of a heterogeneously integrated C-band DFB laser on SOI at 28 Gb/s with a 2 dB extinction ratio. This is the highest direct modulation bitrate so far reported for a membrane laser coupled to an SOI waveguide. The laser operates single mode with 6 mW output power at 100 mA bias current. The 3 dB modulation bandwidth is 15 GHz. Transmission experiments using a 2 km non zero dispersion shifted single mode fiber were performed at 28 Gb/s bitrate using a 2(7)-1 NRZ-PRBS pattern resulting in a 1 dB power penalty. (C) 2015 Optical Society of Americ

Germanium photodetector with monolithically integrated narrowband matching network on a silicon photonics platform

High data rate transceivers typically consist of a system with hybrid integration of the electronics and photonics. Impedance levels provided by the opto-electronic device are often not the same as the levels desired by the electronic circuit. This mismatch introduces suboptimal operation and can even be detrimental for the overall system performance. Consequently, a matching circuit is often implemented on the electronic IC together with the main electronic functionality. Direct RF matching of the opto-electronic devices on the photonic IC has the potential to significantly reduce the overall system cost as the area cost of photonic chips is much lower. In this paper, narrowband LC-matching is shown for a germanium photodetector on the iSiPP50G silicon photonics platform to convert the output impedance to a more standard 50 Ω impedance level at 30 GHz. By tuning the photodetector reverse biasing voltage between 0 Volt and 3 Volt, a reflection coefficient lower than -20 dB is obtained over the frequency range between 24.3 and 30.4 GHz

EAM-based microwave mixer implemented in silicon photonics

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

Silicon photonics radio-over-fiber transmitter using GeSi EAMs for frequency up-conversion

In this letter, we present a silicon photonics radio-over-fiber transmitter with a microwave photonic up-conversion capability. The circuit consists of a pair of parallel GeSi intensity modulators (EAMs) in an MZI structure. We show that the up-converter/transmitter can up-convert 64-QAM data on a 1.5-GHz IF to any output carrier frequency in the 7-26 GHz range. This interval is only limited by the measurement equipment, as we demonstrate that the EAM has a 3-dB bandwidth exceeding 65 GHz. Furthermore, the linearity of the up-converter/transmitter is characterized and a spurious free dynamic range larger than 82 dB center dot Hz(2/3) is demonstrated. Using this system, we transmit up to 1.3-Gb/s 64-QAM data over 2-km SMF with a received 5.4% rms EVM

A 25 Gb/s All-Digital Clock and Data Recovery Circuit for Burst-Mode Applications in PONs

The upcoming 100 Gb/s links in the next-generation ethernet passive optical networks will be based on four channels of 25 Gb/s. The corresponding transceivers in these optical links require a high-speed clock and data recovery circuit to extract a synchronous clock and recover the received data. To achieve a sufficiently fast settling time for 25 Gb/s burst mode upstream applications in passive optical networks (PONs), we introduce an architecture of the first 25 Gb/s all-digital clock and data recovery circuit (AD-CDR). Thanks to the implementation of a digital loop filter, our AD-CDR avoids the need of a system clock or a start-of-burst signal. This circuit is implemented in a 40-nm CMOS process and has a very compact active chip area of only 0.050 mm(2). Furthermore, the performance of the burst-mode operation of our AD-CDR in an optical setup is measured and reported, resulting in a burst-mode lock time of 37.5 ns and consuming only 46 mW

56 Gb/s Electro-Absorption Modulation of a Heterogeneously Integrated InP-on-Si DFB Laser Diode

Electro-absorption modulation of a heterogeneously integrated InP/Si DFB laser is demonstrated by reverse biasing the InP tapers, used to couple the light between the InP and the Si waveguides. Modulation at 56 Gb/s is demonstrated