Passive coherent discriminator using phase diversity for the simultaneous measurement of frequency noise and intensity noise of a continuous-wave laser

The frequency noise and intensity noise of a laser set the performance limits in many modern photonics applications and, consequently, must often be characterized. As lasers continue to improve, the measurement of these noises however becomes increasingly challenging. Current approaches for the characterization of very high-performance lasers often call for a second laser with equal or higher performance to the one that is to be measured, an incoherent interferometer having an extremely long delay-arm, or an interferometer that relies on an active device. These instrumental features can be impractical or problematic under certain experimental conditions. As an alternative, this paper presents an entirely passive coherent interferometer that employs an optical 90° hybrid coupler to perform in-phase and quadrature detection. We demonstrate the technique by measuring the frequency noise power spectral density of a highly-stable 192 THz (1560 nm) fiber laser over five frequency decades. Simultaneously, we are able to measure its relative intensity noise power spectral density and characterize the correlation between its amplitude noise and phase noise. We correct some common misconceptions through a detailed theoretical analysis and demonstrate the necessity to account for normal imperfections of the optical 90° hybrid coupler. We finally conclude that this passive coherent discriminator is suitable for reliable and simple noise characterization of highly-stable lasers, with bandwidth and dynamic range benefits but susceptibility to additive noise contamination.V Michaud-Belleau, H Bergeron, P S Light, N B Hébert, J D Deschênes, A N Luiten and J Genes

Single-frequency mid-infrared waveguide laser

A guided-wave chip laser operating in a single longitudinal mode at 2860 nm is presented. The cavity was set in the Littman-Metcalf configuration to achieve single-frequency operation with a side-mode suppression ratio above 33 dB. The chip laser’s 2 MHz linewidth on a 10 ms scale was found to be limited by mechanical fluctuations, but its Lorentzian contribution was estimated to be lower than 1 Hz using a heterodyne technique. This demonstration incorporates a high coherence source with the simplicity provided by the compactness of chip lasers.Philippe Guay, Jérôme Genest, Vincent Michaud-Belleau, Nicolas Bourbeau Hébert, and David G. Lancaste

Complex direct comb spectroscopy with a virtually imaged phased array

LetterAbstract not availableSarah K. Scholten, James D. Anstie, Nicolas Bourbeau Hébert, Richard T. White, Jérôme Genest, and Andre N. Luite

An ultra-stable 2.9 mu m guided-wave chip laser and application to nano-spectroscopy

We present a configurable guided-wave planar glass-chip laser that produces low-noise and high-quality continuous-wave laser emission tunable from 2.82 to 2.95 µm. The laser has a low threshold and intrinsic power and mode stability attributable to the high overlap of gain volume and pump mode defined by an ultrafast laser inscribed waveguide. The laser emission is single transverse-mode with a Gaussian spatial profile and M²x,y ∼ 1.05, 1.10. The power drift is ∼0.08% rms over ∼2 h. When configured in a spectrally free-running cavity, the guided-wave laser emits up to 170 mW. The benefit of low-noise and stable wavelength emission of this hydroxide resonant laser is demonstrated by acquiring high signal-to-noise images and spectroscopy of a corroded copper surface film with corrosion products containing water and hydroxide ions with a scattering-scanning near-field optical microscope.D.G. Lancaster, D.E. Otten, A. Cernescu, N. Bourbeau Hébert, G.Y. Chen, C.M. Johnson, T.M. Monro, and J. Genes

Dual electro-optic frequency comb spectroscopy using pseudo-random modulation

Abstract not available.Khaoula Fdil, Vincent Michaud-Belleau, Nicolas Bourbeau Hébert, Philippe Guay, Adam J. Fleisher, Jean-Daniel Deschênes, and Jéróme Genes

Ultrafast pulse generation in a mode-locked Erbium chip waveguide laser

Abstract not availableChampak Khurmi, Nicolas Bourbeau Hébert, Wen Qi Zhang, Shahraam Afshar V., George Chen, Jérôme Genest, Tanya M. Monro and David G Lancaste

Staphylococcus lugdunensis, an aggressive coagulase-negative pathogen not to be underestimated

The new emerging coagulase-negative pathogen Staphylococcus lugdunensis is responsible for severe cardiac and joint infections. Since the biochemical phenotypic systems designed for the identification of CoNS do not appear to be species specific and are hardly reliable for the discrimination of S. lugdunensis from other staphylococci, its precise identification requires fine molecular methods. The pathogenic mechanisms by which S. lugdunensis causes severe infections are not yet completely elucidated and in this review its virulence and toxic determinants are surveyed as well as its adhesins and biofilm production