This work reports on the high performance of a 1.3 μm hybrid quantum dot frequency comb laser. Th... more This work reports on the high performance of a 1.3 μm hybrid quantum dot frequency comb laser. The material parameters such as gain, differential gain, and linewidth enhancement factor are studied and linked to the comb dynamics. In particular, results show that a larger linewidth enhancement factor is more beneficial for comb operation; moreover, we demonstrate that, by employing optical injection, both the 3-dB bandwidth and the flatness of the whole optical frequency comb is improved. Such novel findings give promising guidelines for the development of high-speed dense wavelength division multiplexing photonic integrated circuits in upcoming 5G telecommunications and datacom applications.
Graphene is attractive for realizing optoelectronic devices, including photodetectors because of ... more Graphene is attractive for realizing optoelectronic devices, including photodetectors because of the unique advantages. It can easily co-work with other semiconductors to form a Schottky junction, in which the photo-carrier generated by light absorption in the semiconductor might be transported to the graphene layer efficiently by the build-in field. It changes the graphene conduction greatly and provides the possibility of realizing a graphene-based conductive-mode photodetector. Here we design and demonstrate a silicon-graphene conductive photodetector with improved responsivity and response speed. An electrical-circuit model is established and the graphene-sheet pattern is designed optimally for maximizing the responsivity. The fabricated silicon-graphene conductive photodetector shows a responsivity of up to ~105A/W at room temperature (27 °C) and the response time is as short as ~30 μs. The temperature dependence of the silicon-graphene conductive photodetector is studied for t...
2019 Asia Communications and Photonics Conference (ACP), 2019
We present proof-of-concept work towards an integrated multi-λ optical injection locked system-on... more We present proof-of-concept work towards an integrated multi-λ optical injection locked system-on-chip using just one master laser. Tremendous improvement of direct modulation (4_20 Gb/s) and single-mode operation on slave microring laser was achieved.
Silicon photonics is becoming a mainstream data-transmission solution for next-generation data ce... more Silicon photonics is becoming a mainstream data-transmission solution for next-generation data centers, high-performance computers, and many emerging applications. The inefficiency of light emission in silicon still requires the integration of a III/V laser chip or optical gain materials onto a silicon substrate. A number of integration approaches, including flip-chip bonding, molecule or polymer wafer bonding, and monolithic III/V epitaxy, have been extensively explored in the past decade. Here, we demonstrate a novel photonic integration method of epitaxial regrowth of III/V on a III/V-on-SOI bonding template to realize heterogeneous lasers on silicon. This method decouples the correlated root causes, i.e., lattice, thermal, and domain mismatches, which are all responsible for a large number of detrimental dislocations in the heteroepitaxy process. The grown multi-quantum well vertical p–i–n diode laser structure shows a significantly low dislocation density of 9.5 × 104 cm−2, two...
This paper reviews the recent progress of hybrid silicon evanescent devices. The hybrid silicon e... more This paper reviews the recent progress of hybrid silicon evanescent devices. The hybrid silicon evanescent device structure consists of III-V epitaxial layers transferred to silicon waveguides through a low-temperature wafer bonding process to achieve optical gain, absorption, and modulation efficiently on a silicon photonics platform. The low-temperature wafer bonding process enables fusion of two different material systems without degradation of material quality and is scalable to wafer-level bonding. Lasers, amplifiers, photodetectors, and modulators have been demonstrated with this hybrid structure and integration of these individual components for improved optical functionality is also presented. This approach provides a unique way to build photonic active devices on silicon and should allow application of silicon photonic integrated circuits to optical telecommunication and optical interconnects.
ABSTRACT A bending directional coupler is presented to enhance the evanescent coupling between a ... more ABSTRACT A bending directional coupler is presented to enhance the evanescent coupling between a compact deeply-etched III–V/Si hybrid microring laser and its small Si bus waveguide. With the present design, one could realize a sufficient evanescent coupling between the III–V/Si hybrid microring even when the gap between the microring and the bus waveguide is relatively large gap (∼ 400nm).This makes the fabrication easier.
This work reports on the high performance of a 1.3 μm hybrid quantum dot frequency comb laser. Th... more This work reports on the high performance of a 1.3 μm hybrid quantum dot frequency comb laser. The material parameters such as gain, differential gain, and linewidth enhancement factor are studied and linked to the comb dynamics. In particular, results show that a larger linewidth enhancement factor is more beneficial for comb operation; moreover, we demonstrate that, by employing optical injection, both the 3-dB bandwidth and the flatness of the whole optical frequency comb is improved. Such novel findings give promising guidelines for the development of high-speed dense wavelength division multiplexing photonic integrated circuits in upcoming 5G telecommunications and datacom applications.
Graphene is attractive for realizing optoelectronic devices, including photodetectors because of ... more Graphene is attractive for realizing optoelectronic devices, including photodetectors because of the unique advantages. It can easily co-work with other semiconductors to form a Schottky junction, in which the photo-carrier generated by light absorption in the semiconductor might be transported to the graphene layer efficiently by the build-in field. It changes the graphene conduction greatly and provides the possibility of realizing a graphene-based conductive-mode photodetector. Here we design and demonstrate a silicon-graphene conductive photodetector with improved responsivity and response speed. An electrical-circuit model is established and the graphene-sheet pattern is designed optimally for maximizing the responsivity. The fabricated silicon-graphene conductive photodetector shows a responsivity of up to ~105A/W at room temperature (27 °C) and the response time is as short as ~30 μs. The temperature dependence of the silicon-graphene conductive photodetector is studied for t...
2019 Asia Communications and Photonics Conference (ACP), 2019
We present proof-of-concept work towards an integrated multi-λ optical injection locked system-on... more We present proof-of-concept work towards an integrated multi-λ optical injection locked system-on-chip using just one master laser. Tremendous improvement of direct modulation (4_20 Gb/s) and single-mode operation on slave microring laser was achieved.
Silicon photonics is becoming a mainstream data-transmission solution for next-generation data ce... more Silicon photonics is becoming a mainstream data-transmission solution for next-generation data centers, high-performance computers, and many emerging applications. The inefficiency of light emission in silicon still requires the integration of a III/V laser chip or optical gain materials onto a silicon substrate. A number of integration approaches, including flip-chip bonding, molecule or polymer wafer bonding, and monolithic III/V epitaxy, have been extensively explored in the past decade. Here, we demonstrate a novel photonic integration method of epitaxial regrowth of III/V on a III/V-on-SOI bonding template to realize heterogeneous lasers on silicon. This method decouples the correlated root causes, i.e., lattice, thermal, and domain mismatches, which are all responsible for a large number of detrimental dislocations in the heteroepitaxy process. The grown multi-quantum well vertical p–i–n diode laser structure shows a significantly low dislocation density of 9.5 × 104 cm−2, two...
This paper reviews the recent progress of hybrid silicon evanescent devices. The hybrid silicon e... more This paper reviews the recent progress of hybrid silicon evanescent devices. The hybrid silicon evanescent device structure consists of III-V epitaxial layers transferred to silicon waveguides through a low-temperature wafer bonding process to achieve optical gain, absorption, and modulation efficiently on a silicon photonics platform. The low-temperature wafer bonding process enables fusion of two different material systems without degradation of material quality and is scalable to wafer-level bonding. Lasers, amplifiers, photodetectors, and modulators have been demonstrated with this hybrid structure and integration of these individual components for improved optical functionality is also presented. This approach provides a unique way to build photonic active devices on silicon and should allow application of silicon photonic integrated circuits to optical telecommunication and optical interconnects.
ABSTRACT A bending directional coupler is presented to enhance the evanescent coupling between a ... more ABSTRACT A bending directional coupler is presented to enhance the evanescent coupling between a compact deeply-etched III–V/Si hybrid microring laser and its small Si bus waveguide. With the present design, one could realize a sufficient evanescent coupling between the III–V/Si hybrid microring even when the gap between the microring and the bus waveguide is relatively large gap (∼ 400nm).This makes the fabrication easier.
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Papers by Di Liang