Related papers: Study of tunable resonances in laser beam divergen…
We study tunable refraction of light in one-dimensional periodic lattices induced optically in a photorefractive crystal. We observe experimentally both positive and negative refraction of beams which selectively excite the first or second…
A mode locked fibre laser as a source of ultra-stable pulse train has revolutionised a wide range of fundamental and applied research areas by offering high peak powers, high repetition rates, femtosecond range pulse widths and a narrow…
Decades of work on beam deformation on reflection, and especially on lateral shifts, have spread the idea that a reflected beam is larger than the incident beam. However, when the right conditions are met, a beam reflected by a multilayered…
A disordered structure embedding an active gain material and able to lase is called random laser (RL). The RL spectrum may appear either like a set of sharp resonances or like a smooth line superimposed to the fluorescence. A recent letter…
Slow noise processes, with characteristic timescales ~1s, have been studied in planar superconducting resonators. A frequency locked loop is employed to track deviations of the resonator centre frequency with high precision and bandwidth.…
In this article, we study the non-linear coupling between the stationary (i.e. the beating modulation signal) and transient (i.e. the laser quantum noise) dynamics of a laser subjected to frequency shifted optical feedback. We show how the…
We report on a novel kind of transition in random lasers induced by the geometrical confinement of the emitting material. Different dye doped paper devices with controlled geometry are fabricated by soft-lithography and show two…
We demonstrate a technique for locking the frequency of a tunable diode laser to a ring-cavity resonator. The resonator is stabilized to a diode laser which is in turn locked to an atomic transition, thus giving it absolute frequency…
The terahertz emission from difference-frequency in biased superlattices is calculated with the excitonic effect included. Owing to the doubly resonant condition and the excitonic enhancement, the typical susceptibility can be as large as…
Mechanical resonators are widely used as precision clocks and sensitive detectors that rely on the stability of their eigenfrequencies. The phase noise is determined by different factors ranging from thermal noise and frequency noise of the…
We present a detailed numerical investigation of the tunability of a diffusive random laser when Mie resonances are excited. We solve a multimode diffusion model and calculate multiple light scattering in presence of optical gain which…
Tunable lasers are essential for optical communication, spectroscopy, and precision sensing, where flexible and fast control of the laser wavelength is needed. However, conventional tunable laser systems often rely on mechanical actuation,…
Random lasers with low spatial coherence have important potential applications in high quality imaging and displaying. Here, a random laser with tunable angular spectra is proposed and fabricated through directly coupling an asymmetric…
In a laser, the control of its spectral emission depends on the physical dimensions of the optical resonator, limiting it to a set of discrete cavity modes at specific frequencies. Here, we overcome this fundamental limit by demonstrating a…
Resonances are usually associated with finite systems - the vibrations of clamped strings in a guitar or the optical modes in a cavity defined by mirrors. In optics, resonances may be induced in infinite continuous media via periodic…
Laser resonances play a crucial role in optical and quantum systems because the photons impact the stability and coherence of laser sources. While laser oscillations are typically stable and periodic, the presence of nonlinear effects can…
The mode dynamics of a random laser is investigated in experiment and theory. The laser consists of a ZnCdO/ZnO multiple quantum well with air-holes that provide the necessary feedback. Time-resolved measurements reveal multimode spectra…
High brightness and low coherence laser sources with wideband tunability are essential for many full-field imaging applications aiming for high contrast and speckle free performance. However, this combination of parameters is challenging to…
We report a simple technique for stabilization of a laser frequency at the wings of an atomic resonance. The reference signal used for stabilization issues from interference effects obtained in a low-quality cavity filled with a resonant…
Adiabatic frequency conversion enables fast and efficient tuning of laser light by coupling it into an optical resonator whose eigenfrequency is varied on a timescale shorter than its photon lifetime. In this regime, the optical frequency…