Search results for "cavity"
showing 10 items of 641 documents
Long-wavelength monolithic GaInNAs vertical-cavity optical amplifiers
2004
We report on the continuous-wave amplification characteristics of an optically pumped 1.3-μm multiple-quantum-well GaInNAs-GaAs vertical-cavity semiconductor optical amplifier (VCSOA). The VCSOA structure was monolithically grown by molecular beam epitaxy and operated in reflection mode in a fiber-coupled system. The maximum on-chip gain attained, limited by the onset of laser action, was 15.6 dB at 196 mW of 980-nm pump power. For a chip gain of 10.4 dB, the optical bandwidth was 10.8 GHz and the saturation output power was -9 dBm. By varying the pump laser power, a maximum extinction ratio of 22.3 dB was obtained. Temperature-controlled tuneable operation of the device is also presented a…
GaInNAs/GaAs Bragg-mirror-based structures for novel 1.3μm device applications
2004
We report the use of GaInNAs/GaAs material system for a range of 1.3 μm vertical-cavity devices namely VCSELs, VCSOAs, VECSELs and SESAMs. Using optical pumping, we demonstrate that up to 4 mW of 1290 nm output power can be fibre-coupled from a VCSEL. We also show that tayloring the VCSEL structure allows to produce a monolithic long-wavelength VCSOA with up to 16 dB of gain. We also report the first demonstration of a 1.3 μm VECSEL with more than 0.5 W of CW ouptut power. Finally, annealing effects on the properties of a GaInNAs SBR and modelocking of two Nd:doped solid state lasers using this element are described.
Bidirectional laser cavity solitons
2007
Cavity solitons in optical systems have been studied for two decades in a large variety of optical systems. In principle, bidirectional lasers can emit only unidirectionally in steady state, as the two-mode solution (non null steady state in the two possible emission directions) is an unstable solution (winner-takes-all competition prevents the bidirectional cw emission). But for a wide aperture cavity this is not necessarily true as, in different regions of the transverse (with respect to the propagation axis) direction, emission in different propagation directions could occur if the fronts separating these domains are stable. In fact this is exactly what happens when the cavity losses for…
Coupling evanescently low loss Silicon-on-insulator (SOI) ridge waveguides(WGs) including high Q nanocavities: For light control
2011
We have fabricated a multislotted optical nanoresonator with several spatial field distributions which are all addressable by the wavelength. The reported structure consists in an array of evanescently coupled single mode photonic crystal nanocavities. By using a scanning near-field optical microscope, we quantify the morphology of the different optical mode volumes and show that they consist in grids of light confined at the subwavelength scaleOver the last recent years, optical microcavities have proven their ability to slow down, control and even trap light inside an ultra small volume. Several approaches have led to quality factor (Q) records allowing to reach high photon life-time for …
On chip optical nanotweezing for dielectric particles manipulation
2014
On chips optical nanocavities have become useful tools for trapping and manipulation of colloidal objects. In this thesis we study the nanocavities as building blocks for optical forces, trapping and handling of particles. Proof of concept of trapping dielectric microspheres appears as the starting point of the development of lab on chip. In the first chapter we go through the literature of optical forces in free space and integrated optics. The second chapter presents the experimental tools for the characterization of nanocavities and the set-up developed to perform optical measurements with the colloidal particles. The third chapter describes the proof-of-concept trapping of polystyrene p…
Cascadability and reshaping properties of a saturable absorber inserted inside a RZ transmission line for future 160-Gbit/s all-optical 2R-regenerato…
2007
International audience; In this prospective work, we analyze the behavior of a quantum-well microcavity saturable absorber component cascaded into a 100-km SMF RZ transmission line in order to annihilate the ghost-pulse phenomenon in the following simplified “...010101...” 160-Gbit/s 2-bit pattern at 1555 nm. Recirculating-loop experiments show a maximal ghost-pulse extinction up to 11.6 dB as well as an intensity extinction ratio enhancement higher than 6 dB over at least 800 km of propagation.
Erbium doped optical fiber lasers for magnetic field sensing
2015
In this work two erbium doped optical fiber laser configurations for magnetic field measurement are implemented and compared. The first laser is set-up in a loop configuration and requires only a single FBG (Fiber Bragg Grating), acting as mirror. A second laser employs a simpler linear cavity configuration but requires two FBGs with spectral overlap to form the laser cavity. A bulk magnetostrictive material made of Terfenol-D is attached to the laser FBGs enabling modulation of its operation wavelength by the magnetic field. Moreover, a passive interferometer was developed to demodulate the AC magnetic field information where the corresponding demodulation algorithms were software based. B…
Supercontinuum Q-switched Yb fiber laser using an intracavity microstructured fiber
2009
We report on an intracavity configuration for supercontinuum generation in a Q-switched Yb fiber laser. The supercontinuum laser includes a section of microstructured fiber within the Q-switched laser cavity. With 380 mW of pump power, the supercontinuum laser can emit broadband pulses of 6 microJ energy and 10 ns temporal width, at repetition rates from few hertz up to 2 kHz. The supercontinuum spectrum spans over a wavelength range in excess of 1.4 microm.
Evolutionary algorithm for fiber laser in ultrashort pulse regime
2016
This thesis deals with the generation of ultrashort pulses within a fiber laser cavity through the automatic optimization of its parameters by an evolutionary algorithm. The interest of this subject comes from the difficulty to systematically explore dynamics in a large domain of experimental parameters. We have shown that it is possible to implement an evolutionary algorithm on fiber laser cavity with appropriate precautions. We have experimentally demonstrated for the first time the mode locking of a laser cavity only using the optimization of polarization controllers through an automatic and self-learning procedure. We also have demonstrated that selecting the mode locking from it radio-…
Human exfoliated deciduous teeth and oral mucosa: promising applications in tissue regeneration
2018
In the last three decades, the constantly increasing need for therapies, efficiently preventing and/or treating human diseases, has raised the interest in Regenerative Medicine (RM). RM is based on employing mesenchymal stem cells (MSCs), that showed to have great proliferation, self-renewal and multilineage differentiation potential, in vitro as well as in vivo. The opportunity of an accessible, painless and low-cost reservoir of MSCs constitutes the first important step of a successful regenerative therapy to include in the current clinical practice. Oral cavity has recently demonstrated to contain different MSCs niches: dental pulp from permanent and deciduous teeth, periodontal ligament…