Marc Rensing

Optimized pulse source employing an externally injected gain-switched laser diode in conjunction with a nonlinearly chirped grating

In this paper, we demonstrate the generation of transform-limited short optical pulses, which display excellent spectral and temporal qualities by employing a novel technology, based on an externally injected gain-switched laser in conjunction with a nonlinearly chirped grating. Using this technique, 3.5-ps optical pulses exhibiting a time-bandwidth product (TBP) of 0.45 are generated, which are suitable for use in high-speed 80 Gb/s optical time-division multiplexing (OTDM) communications systems. The numerical integration of a set of rate equations using suitable parameters for the devices used in the experiments were carried out to further confirm the feasibility of the proposed method for developing an optimized pulse source for high-speed photonic systems.

Optical and Electronic Packaging Processes for Silicon Photonic Systems

Fiber optic interconnection processes and hybrid integration of electronic devices for high speed Si photonic systems are presented. Thermal effects arising from these hybrid integration processes are also investigated. An overview of ePIXfab which offers affordable access to an advanced Si photonic foundry service is also presented. This includes the presentation of fundamental photonic packaging design rules which can greatly reduce the time and cost associated with the development of complex Si photonic devices.

Packaged hybrid III-V/silicon SOA

We present a hybrid III-V/silicon SOA, mounted in a planar package, with a fiber-to-fiber gain up to 10 dB, maximum internal gain of 28±2 dB, an internal noise figure of 10-11 dB and an output saturation power around 9 dBm.

A 10G linear burst-mode receiver supporting electronic dispersion compensation for extended-reach optical links

We present a novel 10G linear burst-mode receiver with wide (22.7dB) dynamic range. With electronic dispersion compensation, 3400ps/nm (200km) chromatic dispersion can be tolerated at 2dB penalty in bursty ASE-impaired links using C-band electro-absorption modulators.

Directly Modulated Laser Diode Module Exceeding 10 Gb/s Transmission

A directly modulated laser diode module with over 10 Gb/s transmission and its performance, packaging process, and manufacturability are presented. The butterfly package consists of a V-connector, heat sink, and L-shaped microstrip line (MSL) which includes an integrated impedance matching resistor. The optical system consists of a 1.3- distributed feedback laser and a micro lens with isolator. A large modulation bandwidth of up to 15 GHz was obtained, and the eye diagram for 10 Gb/s modulation was clearly visible. Importantly, using an L-shaped MSL with integrated impedance matching resistor design, the module design is significantly simplified and can provide flexibility to insert various optical coupling systems. Moreover, since the laser was mounted directly on Kovar heat sink, optical output power reduction by thermal effects was 1 dB up to 50°C without active cooling. As a result of the simplified module configuration with flexibility, the module packaging process may be highly efficient for mass production.

Hybrid III-V/Silicon SOA in Optical Network Based on Advanced Modulation Formats

A hybrid III-V/silicon semiconductor optical amplifier (SOA) is presented, which shows a maximum fiber-to-fiber gain of 10 dB and a maximum internal gain around 28 ± 2 dB. The device was fabricated from III-V material wafer-bonded onto a silicon-on-insulator wafer. The optical mode transfers between silicon and III-V waveguides by means of waveguide tapers. Vertical grating couplers are used to connect the SOA to optical fibers. The device was packaged and tested in a transmission experiment. In a loop configuration containing 25 km of single-mode fiber, the SOA amplifies data signals of various modulation formats. Transmission with a bit error rate below the forward error correction limit is demonstrated for up to ten loops using QPSK, six loop using 8QAM, and four loops using 16QAM.

Optical and electronic packaging process for silicon photonic systems

Fibre optic interconnection processes and hybrid integration of electronic devices for high-speed Si photonic systems are presented. An overview of ePIXfab which offers affordable access to an advanced Si photonic foundry service is also presented.

A 10 Gb/s Linear Burst-Mode Receiver in 0.25

This paper presents a 10 Gb/s burst-mode receiver (BMRx) that was designed to have high linearity over a >; 20 dB (optical power) dynamic range. Such a linear BMRx (LBMRx) enables electronic dispersion compensation or multilevel modulation formats in bursty optical links. The LBMRx consists of a variable-gain transimpedance amplifier and a variable-gain post-amplifier. A gain from 47 dBΩ to 85 dBΩ was achieved on a single die. Fast (<; 50ns) gain adjustment is achieved using replica based, feedforward automatic gain control and peak detectors, which are reset between bursts using an external reset signal. A sensitivity of - 23.2 dBm at a bit-error rate of 1.1 × 10-3 was measured using a PIN photodiode. A 0.5 dB penalty is incurred if a 0 dBm burst precedes the burst under consideration; hence the LBMRx can support a dynamic range of 22.7 dB. A 150 ns preamble was used, the guard time between bursts was 25.6 ns. Total harmonic distortion (at 250 MHz) less than 5% was measured for an optical power ranging from - 25&nbsp;dBm to 0 dBm. The chip was designed in a 0.25 μm SiGe:C BiCMOS technology, has an area of 2.4 × 2.1 mm2 and consumes 650 mW from 2.5 V/3.3 V supplies.

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We show the importance of achieving an acceptable level of output side-mode-suppression ratio when generating pulses by using the self-seeded gain-switched technique. Experiments carried out on such pulses exhibiting poor side-mode-suppression ratios that are subsequently filtered to improve the latter demonstrate that they possess an associated level of noise. This buildup of noise with a decreasing inherent side-mode-suppression ratio is noted regardless of the improved output-filtered side-mode-suppression ratio of 35 dB that is maintained. The degradation of the signal is due to the mode partition effect and may render these pulses unsuitable for use in high-speed optical communications systems.

m SiGe:C BiCMOS

This paper begins by describing some commonly used photonic packages. The requirements for optical connections to these packages are then discussed. Photonic packages are different to most electronic packages in that the thermal management requirements usually include maintaining the Photonic Integrated Circuit (PIC) at a fixed, sometimes below ambient, operating temperature rather than with keeping the temperature of a package below an upper limit as with most electronic packages. This means that an active Thermoelectric Module (TEM) based cooling system is required. A thermistor is fitted within the package to provide thermal feedback to the TEM controller. This paper uses finite element modelling to investigate whether there is a good match between the target temperature for the PIC and the temperature registered by the thermistor. The results of the modelling show that the model results are quite stable even with large variations in convection and thermistor thermal properties. The thermistor location influences the temperature measured from the package and its thermal response time, but follows the device temperature well enough to provide the TEM controller with adequate feedback to maintain the PIC at a steady temperature in steady state running conditions.