We report on lateral pin germanium photodetectors selectively grown at the end of silicon waveguides. A very high optical bandwidth, estimated up to 120GHz, was evidenced in 10 µm long Ge photodetectors using three kinds of experimental set-ups. In addition, a responsivity of 0.8 A/W at 1550 nm was measured. An open eye diagrams at 40Gb/s were demonstrated under zero-bias at a wavelength of 1.55 µm.

Zero-bias 40Gbit/s germanium waveguide photodetector on silicon.

The current trend in silicon photonics towards higher levels of integration as well as the model of using CMOS foundries for fabrication are leading to a need for standardization of substrate parameters and fabrication processes In particular, for several established research and development foundries that grant general access, silicon-on-insulator wafers with a silicon thickness of 220 nm have become the standard substrate for which devices and circuits have to be designed In this study we investigate the role of silicon device layer thickness in design optimization of various components that need to be integrated in a typical optical transceiver, including both passive ones for routing, wavelength selection, and light coupling as well as active ones such as monolithic modulators and on-chip lasers produced by hybrid integration We find that in all devices considered there is an advantage in using a silicon thickness larger than 220 nm, either for improved performance or for simplified fabrication processes and relaxed tolerances

/pdf/silicon-photonic-integration-platform-have-we-found-the-4lk4wh8a7v.pdf

Silicon Photonic Integration Platform—Have We Found the Sweet Spot?

This paper summarizes recent advances of integrated hybrid InP/SOI lasers and transmitters based on wafer bonding. At first the integration process of III-V materials on silicon is described. Then the paper reports on the results of single wavelength distributed Bragg reflector lasers with Bragg gratings etched on silicon waveguides. We then demonstrate that, thanks to the high-quality silicon bend waveguides, hybrid III-V/Si lasers with two integrated intra-cavity ring resonators can achieve a wide thermal tuning range, exceeding the C band, with a side mode suppression ratio higher than 40 dB. Moreover, a compact array waveguide grating on silicon is integrated with a hybrid III-V/Si gain section, creating a wavelength-selectable laser source with 5 wavelength channels spaced by 400 GHz. We further demonstrate an integrated transmitter with combined silicon modulators and tunable hybrid III-V/Si lasers. The integrated transmitter exhibits 9 nm wavelength tunability by heating an intra-cavity ring resonator, high extinction ratio from 6 to 10 dB, and excellent bit-error-rate performance at 10 Gb/s.

/pdf/hybrid-iii-v-on-silicon-lasers-for-photonic-integrated-4cv7aax4dc.pdf

Hybrid III--V on Silicon Lasers for Photonic Integrated Circuits on Silicon

Silicon photonics is widely acknowledged as a game-changing technology, driven by the needs of datacom and telecom. Silicon photonics builds on highly capital-intensive manufacturing infrastructure, and mature open-access silicon photonics platforms are translating the technology from research fabs to industrial manufacturing levels. To meet the current market demands for silicon photonics manufacturing, a variety of open-access platforms is offered by CMOS pilot lines, R&D institutes, and commercial foundries. This paper presents an overview of existing and upcoming commercial and noncommercial open-access silicon photonics technology platforms. We also discuss the diversity in these open-access platforms and their key differentiators.

https://biblio.ugent.be/publication/8606034/file/8606037.pdf

Open-Access Silicon Photonics: Current Status and Emerging Initiatives

We report on a heterogeneously integrated InP/silicon-on-insulator (SOI) laser source realized through divinylsiloxane-bis-benzocyclobutene (DVS-BCB) wafer bonding. The hybrid lasers present several new features. The III-V waveguide has a width of only 1.7 μm, reducing the power consumption of the device. The silicon waveguide thickness is 400 nm, compatible with high-performance modulator designs and allowing efficient coupling to a standard 220-nm high index contrast silicon waveguide layer. In order to make the mode coupling efficient, both the III-V waveguide and silicon waveguide are tapered, with a tip width for the III-V waveguide of around 800 nm. These new features lead to good laser performance: a lasing threshold as low as 30 mA and an output power of more than 4 mW at room temperature in continuous-wave operation regime. Continuous wave lasing up to 70°C is obtained.

https://biblio.ugent.be/publication/2986286/file/4398147.pdf

Low-Threshold Heterogeneously Integrated InP/SOI Lasers With a Double Adiabatic Taper Coupler

We report the first Silicon/III-V evanescent laser based on adiabatic mode transformers. The hybrid structure is formed
by two vertically superimposed waveguides separated by a 100nm-thick SiO2 layer. The top waveguide, fabricated in an
InP/InGaAsP-based heterostructure, serves to provide optical gain, and the bottom Si-waveguides system, which
supports all optical functions, is constituted by two tapered rib-waveguides (mode transformers), two distributed Bragg
reflectors (DBR), and a surface-grating coupler. The supermode of this hybrid structure is controlled by an appropriate
design of the tapers located at the edges of the gain region. In the middle part of the devices, almost all the field resides
in the III-V waveguide so that the optical mode experiences maximal gain, while in regions near the III-V facets, mode
transformers ensure an efficient transfer of the power flow towards Si-waveguides. The investigated device operates
under quasi-continuous wave regime. The room temperature threshold current is 100 mA, the side mode suppression
ratio is as high as 20dB, and the fiber-coupled output power is ~7mW.

Electrically driven hybrid Si/III-V lasers based on adiabatic mode transformers

We present CMOS compatible dry etching and nonalloyed ohmic contacts on InP dice on silicon. These developments are validated through the demonstration of a continuous wave Ill-V/Si laser with etched facets and gold free contacts.

CMOS compatible contacts and etching for InP-on-silicon active devices

In this paper we show how III-V semiconductors can benefit from advanced silicon fabrication processes and comply with their environment in particular to achieve electrically pumped III-V on silicon lasers for both intra-chip and off-chip applications.

Hybrid integration for silicon photonics applications

In this paper, we discuss the requirements of direct bonding and show how it can provide photonic electronic integrated circuits including surface grating couplers, Ge photodiodes and energy-efficient hybrid Si/III-V lasers.

Direct bonding for silicon photonics

We present 1.55 mum InGaAsP/InP Fabry-Perot lasers on silicon realized by a die-to-wafer CMOS compatible SiO2/SiO2 bonding process. The devices run under continuous wave operation at room temperature with a maximal output power of 4 mW and a threshold current of 108 mA at 15degC.

P. Philippe

Papers

Electrically driven hybrid Si/III-V lasers based on adiabatic mode transformers

CMOS compatible contacts and etching for InP-on-silicon active devices

Hybrid integration for silicon photonics applications

Direct bonding for silicon photonics

Continuous wave InGaAsP/InP Fabry-Perot lasers on silicon