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Recently, we have demonstrated internal net gain with a bandwidth of 80 nm (1500 - 1580 nm) and 1533 nm peak gain of 2.0 dB/cm in Al2O3:Er3+ channel waveguides which were sputtered on silicon substrates and subsequently reactive ion etched. Based on measured spectroscopic parameters, rate-equation simulations predict gain of >20 dB throughout the entire telecom C-band for optimized waveguide lengths...
In this paper we review some recent results related to the application of ultra-long Raman fibre laser (URFL) cavities to quasi-lossless optical signal transmission. In an URFL, the transmission fibre itself is contained inside a laser cavity delimited by two fibre Bragg gratings, allowing for a more efficient distribution of the Raman gain to the transmitted signal. We explore the unique properties...
We review recent results on wafer fused long wavelength VCSELs emitting in the 1310 - 2000 nm range. This technology allows reaching fundamental mode output in excess of 4.5 mW at room temperature and close to 3 mW at 70degC for both the 1310 nm and 1550 nm wavebands-the highest values obtained so far. Emission wavelength can be tuned continuously with current with a tuning range as large as 15 nm...
We fabricated and characterized a vertical-cavity surface-emitting laser (VCSEL) based on (110) InGaAs/GaAs multiple quantum wells (MQWs). Circularly polarized lasing in the (110) VCSEL by optical injection of spin-polarized electrons has been demonstrated at 77 K and room temperature. A high degree of circular polarization, 0.94, was observed at 77 K, reflecting the long electron spin relaxation...
Here, we emphasize the importance of using a bottom reflector to achieve unidirectional vertical emission from an ultra-small light emitter. Specifically, we have considered a photonic crystal slab nanocavity laser placed in the vicinity of a perfect mirror. By choosing near one-wavelength distance between the bottom reflector and the cavity, over 80% of photons generated inside the laser cavity can...
Circular dielectric cavities are key components for the construction of optic microresonators and microlasers. They are one of very few cases where the transcendental equations for complex eigenmodes (resonances) of an open system (dielectric cavity) can be found analytically in an exact manner. The behaviour of those eigenvalues in the small opening limit, i.e. when the refractive index of the cavity...
We present results on the realization of a dual wavelength micro-spherical glass laser source fabricated from the Erbium doped fluoride glass ZBLALiP. The pump wavelength (1480 nm) is close to that of the laser field (~1550 nm) and we use a half taper to couple both fields in and out the micro-spherical laser. The coupling by two half tapers on the same micro-spherical resonator allows two single...
In this paper, results on processing and characterization of an optically pumped hybrid distributed feedback cavity for C-band applications are presented. Nanoimprinting lithography has been used for grating fabrication. An erbium-doped organic material has been used as active layer. Potential for integration of the DFB cavity into a single mode waveguide operating in the C-band is demonstrated by...
By an improved optimization of the grating profile, an asymmetric three phase-shift (3PS) distributed feedback (DFB) laser structure is shown to achieve stable single mode oscillation up to high current injection levels. The analysis of those structures enhances the possibility of attaining high mode selectivity whilst ensuring almost flat profiles for the intracavity field distribution. The transfer...
In this paper, we propose, through different theoretical examples of composite fibre designs, some alternative ways to push up the limits of active optical fibres. Highly ytterbium-doped large cores are required for high power delivery and low non linear limitations. Such cores usually support several guided modes. We demonstrate in this paper that by surrounding the core with a tailored cladding,...
The development of stable single frequency fiber laser requires the use of short cavity length and therefore high gain per unit length medium. Tellurite glasses possess the suitable properties to realize such a device that would operate in the 2 mum wavelength region. Amongst those properties are low phonon energy and high rare earth ion solubility. The optical and thermo-mechanical properties of...
In this paper passively mode-locked erbium doped fiber laser is described. With all-fiber cavity configuration 169 MHz fundamental repetition frequency and average output power of more than 30 mW were achieved. Output frequency comb spectrum of 28.5 nm and 111 fs pulses were obtained.
In this paper, we study the scattering and eigenvalue problems for a periodic open optical resonator that is an infinite chain of active circular cylindrical quantum wires standing in free space. The scattering problem is solved by the method of partial separation of variables. The eigenvalue problem differs from the first one by the absence of the incident field and presence of ldquoactive propertiesrdquo...
We report passive mode-locking of a soliton erbium-doped double-clad fiber laser operating at the 322nd harmonic of the fundamental cavity frequency. Repetition rates scalable up to 3 GHz have been obtained with a pulse duration of about 1 ps and a pulse energy of about 18 pJ. The supermode suppression at the 322nd harmonic is better than 25 dB. The dynamics of emergence of this operating regime is...
We present a formalism for calculating the multiple-quantum-dot-photon dynamics in coupled-cavity photonic crystal slab systems by projecting the Hamiltonian onto non-orthogonal photon quasimodes and applying the quantum jump technique. We apply this approach to the correlated emission by two quantum dots and demonstrate the importance of the non-orthogonality of the quasimodes.
We demonstrate first experimental evidence of polarization switching in Stranski-Krastanov (SK) and submonolayer (SML) quantum dot (QD) vertical-cavity surface-emitting lasers (VCSELs). In the case of a SMLQD VCSEL polarization switching is accompanied by polarization mode hopping and is associated with a change of linearly polarized light to elliptically polarized one, hence switching takes place...
Fiber lasers based on praseodymium-ytterbium doped fluoride glass fibers with silica fiber pigtails offer a wide range of different configurations. Here we present results of such fiber lasers in different ring configurations in an all-fiber setup. The fiber lasers are pumped with pigtailed laser diodes at 845 nm and deliver output powers up to 20 mW at 635 nm.
Three methods to obtain in GaAs-based oxide-confined GaInNAs/GaAs quantum-well (QW) VCSELs an efficient emission of the 1.3-mum radiation have been analysed and compared with the aid of the comprehensive fully self-consistent model. In the tuned VCSEL, QW composition (high N content) and thickness are selected to tune the 1.3-mum emission which ensures low threshold currents. However, manufacturing...
In the present paper, the comprehensive self-consistent VCSEL physical model is used to analyse excitation of successive transverse cavity modes in oxide-confined (OC) vertical-cavity surface-emitting diode lasers (VCSELs) using the double intra-cavity-contacted 5-lambda-cavity double-quantum-well GaAs-based GaInNAs/GaAs OC VCSEL emitting the 1.3-mum radiation as a typical VCSEL example. As expected,...
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