4,373 research outputs found
Vertical-external-cavity surface-emitting lasers and quantum dot lasers
The use of cavity to manipulate photon emission of quantum dots (QDs) has
been opening unprecedented opportunities for realizing quantum functional
nanophotonic devices and also quantum information devices. In particular, in
the field of semiconductor lasers, QDs were introduced as a superior
alternative to quantum wells to suppress the temperature dependence of the
threshold current in vertical-external-cavity surface-emitting lasers
(VECSELs). In this work, a review of properties and development of
semiconductor VECSEL devices and QD laser devices is given. Based on the
features of VECSEL devices, the main emphasis is put on the recent development
of technological approach on semiconductor QD VECSELs. Then, from the viewpoint
of both single QD nanolaser and cavity quantum electrodynamics (QED), a
single-QD-cavity system resulting from the strong coupling of QD cavity is
presented. A difference of this review from the other existing works on
semiconductor VECSEL devices is that we will cover both the fundamental aspects
and technological approaches of QD VECSEL devices. And lastly, the presented
review here has provided a deep insight into useful guideline for the
development of QD VECSEL technology and future quantum functional nanophotonic
devices and monolithic photonic integrated circuits (MPhICs).Comment: 21 pages, 4 figures. arXiv admin note: text overlap with
arXiv:0904.369
Purcell Effect in the Stimulated and Spontaneous Emission Rates of Nanoscale Semiconductor Lasers
Nanoscale semiconductor lasers have been developed recently using either
metal, metallo-dielectric or photonic crystal nanocavities. While the
technology of nanolasers is steadily being deployed, their expected performance
for on-chip optical interconnects is still largely unknown due to a limited
understanding of some of their key features. Specifically, as the cavity size
is reduced with respect to the emission wavelength, the stimulated and the
spontaneous emission rates are modified, which is known as the Purcell effect
in the context of cavity quantum electrodynamics. This effect is expected to
have a major impact in the 'threshold-less' behavior of nanolasers and in their
modulation speed, but its role is poorly understood in practical laser
structures, characterized by significant homogeneous and inhomogeneous
broadening and by a complex spatial distribution of the active material and
cavity field. In this work, we investigate the role of Purcell effect in the
stimulated and spontaneous emission rates of semiconductor lasers taking into
account the carriers' spatial distribution in the volume of the active region
over a wide range of cavity dimensions and emitter/cavity linewidths, enabling
the detailed modeling of the static and dynamic characteristics of either
micro- or nano-scale lasers using single-mode rate-equations analysis. The
ultimate limits of scaling down these nanoscale light sources in terms of
Purcell enhancement and modulation speed are also discussed showing that the
ultrafast modulation properties predicted in nanolasers are a direct
consequence of the enhancement of the stimulated emission rate via reduction of
the mode volume.Comment: 12 pages, 5 figure
Photonic crystal chips for optical communications and quantum information processing
We discuss recent our recent progress on functional photonic crystals devices and circuits for classical and quantum information processing. For classical applications, we have demonstrated a room-temperature-operated, low threshold, nanocavity laser with pulse width in the picosecond regime; and an all-optical switch controlled with 60 fJ pulses that shows switching time on the order of tens of picoseconds. For quantum information processing, we discuss the promise of quantum networks on multifunctional photonic crystals chips. We also discuss a new coherent probing technique of quantum dots coupled to photonic crystal nanocavities and demonstrate amplitude and phase nonlinearities realized with control beams at the single photon level
Modeling an Electrically Driven Graphene-Nanoribbon Laser for Optical Interconnects
Graphene has two very important optical properties of population inversion of
electrons, and broadband optical gain. As a result, graphene has potential for
use in lasers and amplifiers. In this work, we presented a quantum master model
and analyzed the properties for the electrically pumped single-AGNR
vertical-cavity surface-emitting lasers (VCSELs) to investigate the lasing
action and laser properties for realistic experimental parameters. A
semiclassical approximation for the output power and laser linewidth is also
derived. The laser threshold power was several orders of magnitude lower than
that currently achievable with semiconductor microlasers. Our results have
demonstrated that a single-AGNR VCSEL can serve as a nanolaser with ultralow
lasing threshold. Implementation of such a GNR-based VCSEL is especially
promising for optical interconnection systems since VCSELs emit low optical
power and single longitudinal mode over a wide wavelength spectral range
through tailoring GNRs.Comment: 5 pages, 4 figures,
http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=6458072&tag=
Multimode optical feedback dynamics in InAs/GaAs quantum dot lasers emitting exclusively on ground or excited states: transition from short- to long-delay regimes
© 2018 Optical Society of America. Users may use, reuse, and build upon the article, or use the article for text or data mining, so long as such uses are for non-commercial purposes and appropriate attribution is maintained. All other rights are reserved.The optical feedback dynamics of two multimode InAs/GaAs quantum dot lasers emitting exclusively on sole ground or excited lasing states is investigated. The transition from long- to short-delay regimes is analyzed, while the boundaries associated to the birth of periodic and chaotic oscillations are unveiled to be a function of the external cavity length. The results show that depending on the initial lasing state, different routes to chaos are observed. These results are of importance for the development of isolator-free transmitters in short-reach networks
Deterministic polarization chaos from a laser diode
Fifty years after the invention of the laser diode and fourty years after the
report of the butterfly effect - i.e. the unpredictability of deterministic
chaos, it is said that a laser diode behaves like a damped nonlinear
oscillator. Hence no chaos can be generated unless with additional forcing or
parameter modulation. Here we report the first counter-example of a
free-running laser diode generating chaos. The underlying physics is a
nonlinear coupling between two elliptically polarized modes in a
vertical-cavity surface-emitting laser. We identify chaos in experimental
time-series and show theoretically the bifurcations leading to single- and
double-scroll attractors with characteristics similar to Lorenz chaos. The
reported polarization chaos resembles at first sight a noise-driven mode
hopping but shows opposite statistical properties. Our findings open up new
research areas that combine the high speed performances of microcavity lasers
with controllable and integrated sources of optical chaos.Comment: 13 pages, 5 figure
Advances in small lasers
M.T.H was supported by an Australian Research council Future Fellowship research grant for this work. M.C.G. is grateful to the Scottish Funding Council (via SUPA) for financial support.Small lasers have dimensions or modes sizes close to or smaller than the wavelength of emitted light. In recent years there has been significant progress towards reducing the size and improving the characteristics of these devices. This work has been led primarily by the innovative use of new materials and cavity designs. This Review summarizes some of the latest developments, particularly in metallic and plasmonic lasers, improvements in small dielectric lasers, and the emerging area of small bio-compatible or bio-derived lasers. We examine the different approaches employed to reduce size and how they result in significant differences in the final device, particularly between metal- and dielectric-cavity lasers. We also present potential applications for the various forms of small lasers, and indicate where further developments are required.PostprintPeer reviewe
Photonic crystal chips for optical interconnects and quantum information processing
We have recently demonstrated a number of functional photonic crystals devices and circuits, including an ultrafast, room temperature, low threshold, nanocavity laser with the direct modulation speed approaching 1 THz, an all-optical switch controlled with 60 fJ pulses and with the speed exceeding 200Hz, and a local, reversible tuning of individual quantum dots on a photonic crystal chip by up to 1.8nm, which was then used to tune single quantum dots into strong coupling with a photonic crystal cavity and to achieve a giant optical nonlinearity
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