Chao-Yuan Jin | The University of Sheffield (original) (raw)

Papers by Chao-Yuan Jin

Asia Communications and Photonics Conference 2013, 2013

This paper discusses fundamental limits in photonic switching devices taking into account of the ... more This paper discusses fundamental limits in photonic switching devices taking into account of the material's optical nonlinearity as well as optical field enhancement within the device structures. Quantum dot materials in corporation with optical cavity structures are expected to be a powerful combination for ultrafast, energy-efficient photonic switches. Recent demonstration of fJ/cm 2 class switching in QD-based vertical cavity structure is described.

The real-time manipulation of electromagnetic fields is fundamentally important to cavity quantum... more The real-time manipulation of electromagnetic fields is fundamentally important to cavity quantum electrodynamics (CQED) studies since the matter-field interaction forms the basis of CQED effects and generally of all radiative processes used in classical and quantum photonics. In quantum information systems based on semiconductor artificial atoms, e.g. quantum dots (QDs), the single photons carrying information within the distributed quantum network have to be stored, processed and retrieved within the radiative lifetime of carriers in QDs and the coherence time of the quantum node, which requires sub-nanosecond manipulation in order to achieve high efficiency.

2006 IEEE 20th International Semiconductor Laser Conference, 2006. Conference Digest., 2006

We measure the temperature dependence of the components of threshold current of 1300nm undoped an... more We measure the temperature dependence of the components of threshold current of 1300nm undoped and p-doped quantum-dot-lasers and show that the temperature dependence of gain is the largest factor in producing the observed negative T 0 .

Conference on Lasers and Electro-Optics, 2007, CLEO 2007, 2007

A quaternary-barrier structure is employed to reduce the strain at the interface between the quan... more A quaternary-barrier structure is employed to reduce the strain at the interface between the quantum well and barriers for GaInNAs/GaAs materials. A very-low room-temperature threshold current density of 178A/cm 2 is demonstrated with 1.34-μm GaInNAs/GaAs lasers.

Conference on Quantum Electronics and Laser Science (QELS) - Technical Digest Series, 2007

A room-temperature negative characteristic temperature is demonstrated for a p-type modulation do... more A room-temperature negative characteristic temperature is demonstrated for a p-type modulation doped 1.3-μm quantum dot laser. A photon coupling mechanism is purposed to explain the temperature-dependent J th for both p-doped and un-doped QD lasers.

Conference Proceedings - International Conference on Indium Phosphide and Related Materials, 2009

Self-assembled InAs/GaAs quantum dots (QD) incorporated in a GaAs/AlAs Fabry-Pérot cavity have be... more Self-assembled InAs/GaAs quantum dots (QD) incorporated in a GaAs/AlAs Fabry-Pérot cavity have been employed as an optical nonlinear source for vertical-reflection type switches. Switching times of 32~80 ps have been achieved in this novel structure. All-optical switching using excited QD states shows better performance due to fast carrier relaxation between QD energy states. These results demonstrate potential application of QD materials in ultra-fast alloptical switching devices.

Conference on Lasers and Electro-Optics 2012, 2012

ABSTRACT We have demonstrated optical control of quality-factor (Q-factor) using coupled photonic... more ABSTRACT We have demonstrated optical control of quality-factor (Q-factor) using coupled photonic crystal cavities. A double heterostructure (DHS) cavity has been thermo-optically brought in resonance to an adjacent Febry-Pérot cavity to reduce the optical confinement and hence decrease the Q-factor. Both the strong and weak coupling phenomena between two cavities have been studied. Up to 50% Q-factor change has been experimentally observed. The corresponding modification of the local density of states enables the control of the spontaneous emission rate of the quantum emitters in the DHS cavity.

Applied Physics Letters, 2007

ABSTRACT The authors report the creation of low reflectivity angled facets by focused-ion-beam po... more ABSTRACT The authors report the creation of low reflectivity angled facets by focused-ion-beam postfabrication etching. A method to directly measure the effective facet reflectivity of such facets, utilizing gain saturation effects in the quantum dots is described. The reflectivities of the angled facets are shown to decrease by increasing the facet angle from 0° to 15°. With a reflectivity of ≪1×10-6 obtained for a facet with a 15° angle, allowing quantum dot superluminescent light-emitting diodes to be fabricated. The use of different angled facets to control the emission wavelength of both quantum dot lasers and superluminescent light-emitting diodes is outlined.

This special issue of Optics & Photonics News highlights the most exciting peer-reviewed optics r... more This special issue of Optics & Photonics News highlights the most exciting peer-reviewed optics research to have emerged over the past 12 months.

The radiative interaction of solid-state emitters with cavity fields is the basis of semiconducto... more The radiative interaction of solid-state emitters with cavity fields is the basis of semiconductor microcavity lasers and cavity quantum electrodynamics (CQED) systems. Its control in real time would open new avenues for the generation of non-classical light states, the control of entanglement and the modulation of lasers. However, unlike atomic CQED or circuit quantum electrodynamics, the real-time control of radiative processes has not yet been achieved in semiconductors because of the ultrafast timescales involved. Here we propose an ultrafast non-local moulding of the vacuum field in a coupled-cavity system as an approach to the control of radiative processes and demonstrate the dynamic control of the spontaneous emission (SE) of quantum dots (QDs) in a photonic crystal (PhC) cavity on a ∼200 ps timescale, much faster than their natural SE lifetimes.

Chao-Yuan Jin and Osamu Wada, Apr 2, 2014

Focusing and guiding light into semiconductor nano-structures can deliver revolutionary concepts ... more Focusing and guiding light into semiconductor nano-structures can deliver revolutionary concepts for photonic devices, which offer a practical pathway towards next-generation power-efficient optical networks. In this review, we consider the prospects for photonic switches using semiconductor quantum dots (QDs) and photonic cavities which possess unique properties based on their low dimensionality. The optical nonlinearity of such photonic switches is theoretically analysed by introducing the concept of a field enhancement factor. This approach reveals a drastic improvement in both power-density and speed, which is able to overcome the limitations that have beset conventional photonic switches for decades. In addition, the overall power consumption is reduced due to the atom-like nature of QDs, as well as the nano-scale footprint of photonic cavities. Based on this theoretical perspective, the current state-of-the-art QD/cavity switches are reviewed in terms of various optical nonlinearity phenomena that have been utilized to demonstrate photonic switching. Emerging techniques, enabled by cavity nonlinear effects such as wavelength tuning, Purcell-factor tuning and plasmonic effects, are also discussed.

CY Jin, MY Swinkels, R Johne, TB Hoang, L Midolo, PJ van Veldhoven, A Fiore

We demonstrate the remote all-optical control of the spontaneous emission (SE) of quantum dots us... more We demonstrate the remote all-optical control of the spontaneous emission (SE) of quantum dots using coupled photonic crystal cavities. By spectrally tuning a Fabry-Perot cavity in resonance with a target cavity, the quality factor and the local density of states experienced by emitters in the target cavity are modified, leading to a change in the SE rate. From the theoretical analysis of the coupled-cavity quantum electrodynamics system, the SE rate change can be higher than the quality factor change due to a reduction of the vacuum field at the emitter's position when the two cavities are brought in resonance. Both the weak and strong coupling regimes of two cavities have been observed experimentally and the SE decay rate has been modified by more than a factor of three with remote optical control.

Jiayue Yuan, C. Y. Jin, Matthias Skacel, Adam Urbanczyk, Tian Xia, P. J. van Veldhoven and Richard Notzel, May 2013

We report strongly modified optical emission of InAs/InP quantum dots (QDs) coupled to the surfac... more We report strongly modified optical emission of InAs/InP quantum dots (QDs) coupled to the surface plasmon resonance (SPR) of In nanoparticles grown by metal-organic vapor phase epitaxy. With increasing In deposition time, the In nanoparticle size increases and the SPR redshifts significantly. When overlapping with the SPR, the excited state photoluminescence of the QDs is strongly enhanced due to QD-SPR coupling while the ground state photoluminescence is quenched due to non-radiative energy transfer. This is underpinned by the wavelength dependence of the spontaneous emission decay time which shows an opposite trend compared to that of bare QDs.

Chao-Yuan Jin, Mark Hopkinson, Osamu Kojima, Takashi Kita, Kouichi Akahane and Osamu Wada, 2012

Photonic devices employing semiconductor quantum dots (QDs) are anticipated to play an important ... more Photonic devices employing semiconductor quantum dots (QDs) are anticipated to play an important role within power-efficient optical networks. In this chapter, we consider the prospects for signal processing using all-optical QD switches. Vertical cavity structures have been developed to enhance the light-QD interaction and accordingly the optical nonlinearity of QDs which leads to low energy consumption. Such structures show great potential for the realization of power-efficient, polarization-insensitive and micrometer-size switching devices for future photonic signal processing systems.

Jiayue Yuan, Hao Wang, René P. J. van Veldhoven, Jia Wang, Tjibbe de Vries, Barry Smalbrugge, C. Y. Jin, Peter Nouwens, Erik Jan Geluk, Andrei Yu. Silov, and Richard Nötzel, May 2011

We report on the shape and polarization control of site-controlled multiple and single InAs quant... more We report on the shape and polarization control of site-controlled multiple and single InAs quantum dots QDs on InP pyramids grown by selective-area metal-organic vapor phase epitaxy. With increasing growth temperature the QDs elongate causing strong linear polarization of the photoluminescence. With reduced pyramid base/pyramid top area/QD number, the degree of polarization decreases, attributed to the symmetric pyramid top, reaching zero for single QDs grown at lower temperature. This control of linear polarization is important for entangled photon sources operating in the 1.55u m wavelength region.

C. Y. Jin, O. Kojima, T. Kita, O. Wada, and M. Hopkinson, Jun 2011

We have studied the possibility to utilize semiconductor quantum dots (QDs) as an optical phase s... more We have studied the possibility to utilize semiconductor quantum dots (QDs) as an optical phase shifter within a vertical geometry for ultrafast information processing. From theoretical analyses, an optical phase nonlinearity in QD structures has been predicted which can be enhanced through the use of an vertical optical cavity. Asymmetric cavity structures with 16/30 periods of GaAs/AlGaAs layers for the front/back mirrors have been fabricated to demonstrate a practical device with significant nonlinear characteristics for optical switching. A phase shift of 18° has been initially observed with a tilted pump scheme. This observation paves the way toward a Mach–Zehnder optical switch using QDs inside a vertical cavity.

Chao-Yuan Jin, Osamu Kojima, Tomoya Inoue, Takashi Kita, Osamu Wada, Fellow, IEEE, Mark Hopkinson, and Kouichi Akahane, Jun 2010

We propose an all-optical switch based on self- assembled InAs/GaAs quantum dots (QDs) within a ... more We propose an all-optical switch based on self-
assembled InAs/GaAs quantum dots (QDs) within a vertical cavity. Two essential aspects of this novel device have been investigated, which includes the QD/cavity nonlinearity with appropriately designed mirrors and the intersubband carrier dynamics inside QDs. Vertical-reflection-type switches have been fabricated with an asymmetric cavity that consists of 12 periods of GaAs/Al0.8Ga0.2As for the front mirror and 25 periods for the back mirror. All-optical switching via the QD excited states has been achieved with a time constant down to 23 ps, wavelength tunability over 30 nm, and ultralow power consumption less than 1 fJ/µm2. These results demonstrate that QDs within a vertical cavity have great advantages to realize low-power- consumption polarization-insensitive micrometer-sized switching devices for the future optical communication and signal process- ing systems.