In this paper, we present a novel Brillouin fiber-ring laser utilizing an unbalanced Mach–Zehnder interferometer (UMZI) as coupling device. The laser is pumped by a distributed-feedback laser diode and shows continuous-wave and single-frequency operation. Frequency-dependent transmission characteristics of the UMZI make it possible for the pump wave to pass through the laser-ring cavity with no...

This paper describes measurements and simulations related to power fluctuations of the laser light in the GEO 600 laser-interferometric gravitational wave detector. Measurements of the relative fluctuations of the light power at three different ports of the main interferometer are presented. In addition, measurements and simulations of the coupling transfer functions from power fluctuations at ...

We investigate the performance of distributed acoustic sensing over multi-mode fibers based on heterodyne phase-sensitive optical time-domain reflectometry. report a mathematical model describing relation between phase variation and applied strain in presence propagation that supports feasibility measurements fibers. also propose novel coherent averaging method achieves up to three-fold reducti...

In this work, we present a novel interferometer based on liquid crystal and photonic crystal fiber technology. The objective of this project is the development of a tunable (switchable) modal (MachZehnder) interferometer for optical communications or sensing. This interferometer has been manufactured splicing a short portion (between 15 and 30 mm) of photonic crystal fiber with two single mode ...

The problem of estimating a generic phase-shift experienced by a quantum state is addressed for a generally degenerate phase shift operator. The optimal positive operator-valued measure is derived along with the optimal input state. Two relevant examples are analyzed: i) a multi-mode phase shift operator for multipath interferometry; ii) the two mode heterodyne phase detection.

We report on the development and characterization of the new compact infrared heterodyne receiver, iChips (Infrared Compact Heterodyne Instrument for Planetary Science). It is specially designed for ground-based observations of the terrestrial atmosphere in the mid-infrared wavelength region. Mid-infrared room temperature quantum cascade lasers are implemented into a heterodyne system for the f...

An investigation is performed of the possibility of achieving simultaneous distributed strain and temperature sensing based on hybrid Raman–Brillouin scattering with the use of multi-wavelength optical sources such as common Fabry–Perot (FP) lasers. By employing a self-heterodyne detection scheme based on a multi-wavelength optical local oscillator, the benefits of FP lasers are fully exploited...

The principle of an atomic interferometer based on the longitudinal Stem-Gerlach