The induced nonlinear electric dipole and higher moments in an atomic system, irradiated simultaneously by two or three light waves, are calculated by quantum-mechanical perturbation theory. Terms quadratic and cubic in the field amplitudes are included. An important permutation symmetry relation for the nonlinear polarizability is derived and its frequency dependence is discussed. The nonlinear microscopic properties are related to an effective macroscopic nonlinear polarization, which may be incorporated into Maxwell's equations for an infinite, homogeneous, anisotropic, nonlinear, dielectric medium. Energy and power relationships are derived for the nonlinear dielectric which correspond to the Manley-Rowe relations in the theory of parametric amplifiers. Explicit solutions are obtained for the coupled amplitude equations, which describe the interaction between a plane light wave and its second harmonic or the interaction between three plane electromagnetic waves, which satisfy the energy relationship ${\ensuremath{\omega}}_{3}={\ensuremath{\omega}}_{1}+{\ensuremath{\omega}}_{2}$, and the approximate momentum relationship ${\mathrm{k}}_{3}={\mathrm{k}}_{1}+{\mathrm{k}}_{2}+\ensuremath{\Delta}\mathrm{k}$. Third-harmonic generation and interaction between more waves is mentioned. Applications of the theory to the dc and microwave Kerr effect, light modulation, harmonic generation, and parametric conversion are discussed.

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Interactions between Light Waves in a Nonlinear Dielectric

This paper is an overview of current gyroscopes and their roles based on their applications. The considered gyroscopes include mechanical gyroscopes and optical gyroscopes at macro- and micro-scale. Particularly, gyroscope technologies commercially available, such as Mechanical Gyroscopes, silicon MEMS Gyroscopes, Ring Laser Gyroscopes (RLGs) and Fiber-Optic Gyroscopes (FOGs), are discussed. The main features of these gyroscopes and their technologies are linked to their performance.

Gyroscope Technology and Applications: A Review in the Industrial Perspective

Photonics for angular rate sensing is a well-established research field having very
 important industrial applications, especially in the field of strapdown inertial
 navigation. Recent advances in this research field are reviewed. Results obtained in
 the past years in the development of the ring laser gyroscope and the fiber optic
 gyroscope are presented. The role of integrated optics and photonic integrated
 circuit technology in the enhancement of gyroscope performance and compactness is
 broadly discussed. Architectures of new slow-light integrated angular rate sensors
 are described. Finally, photonic gyroscopes are compared with other solid-state
 gyros, showing their strengths and weaknesses.

Photonic technologies for angular velocity sensing

Over the last two decades a series of large ring laser gyroscopes have been built having an unparalleled scale factor. These upscaled devices have improved the sensitivity and stability for rotation rate measurements by six orders of magnitude when compared to previous commercial developments. This progress has made possible entirely new applications of ring laser gyroscopes in the fields of geophysics, geodesy, and seismology. Ring lasers are currently the only viable measurement technology, which is directly referenced to the instantaneous rotation axis of the Earth. The sensor technology is rapidly developing. This is evidenced by the first experimentally viable proposals to make terrestrial tests of general relativistic effects such as the frame dragging of the rotating Earth.

Invited Review Article: Large ring lasers for rotation sensing

Optical structures and method for producing tunable waveguide lasers. In one embodiment, a waveguide is defined within a glass substrate doped with a rare-earth element or elements by ion diffusion. Feedback elements such as mirrors or reflection gratings in the waveguide further define a laser-resonator cavity so that laser light is output from the waveguide when pumped optically or otherwise. Means are disclosed for varying the wavelengths reflected by the reflection gratings and varying the effective length of the resonator cavity to thereby tune the laser to a selected wavelength. Apparatus and method for integrating rare-earth doped lasers and optics on glass substrates. The invention includes a laser component formed from a glass substrate doped with a optically active lanthanides species with a plurality of waveguides defined by channels within the substrate. The laser component may constitute a monolithic array of individual waveguides in which the waveguides of the array form laser resonator cavities with differing resonance characteristics. The channels defining the waveguides are created by exposing a surface of the substrate to an ion-exchange solvent through a mask layer having a plurality of line apertures corresponding to the channels which are to be formed.

Method and apparatus for waveguide optics and devices

We report the theoretical and experimental investigation of the effects of mode coupling in a resonant macroscopic quantum device, in the case of a solid-state ring laser. This is achieved by introducing an additional coupling source whose interplay with the already-existing nonlinear effects ensures the coexistence of two counterpropagating cavity modes yielding a rotation-sensitive beat note. The determination of the condition for rotation sensing, both theoretically and experimentally, allows a quantitative study of the role of various mode-coupling mechanisms, in particular, the gain-induced mode coupling. We point out the connection between our work and the theoretical work on mode coupling in superfluid devices. This work opens up the possibility of new types of active rotation sensors.

https://hal.archives-ouvertes.fr/hal-00020537/document

Mode-Coupling Control in Resonant Devices: Application to Solid-State Ring Lasers

https://hal.archives-ouvertes.fr/hal-00934642/document

Modelling of the erbium-ytterbium laser.

Disclosed is a power laser in which several laser diodes emit pump beams towards amplifier media. The beams coming from these amplifier media are combined by an optical system to give a common beam transmitted to an output mirror. The mirror and a reflecting face of each amplifier forms an optical cavity.

Power lasers pumped by laser diodes

A miniature optical source which includes at least one thin film of active laser materials having, in addition, non-linear properties A pump laser for emitting a beam of a wavelength allowing for the pumping of the thin film of active laser material perpendicularly to the plane of the thin film Also, an optical cavity constituted by two mirrors whose coefficients of reflection are maximum at the laser wavelength of the active laser material is further provided The miniature optical source may find particular application in a physically compact laser emitting in the visible spectrum

Miniature optical source

We report for the first time (to our knowledge) the experimental achievement of a single-frequency ring-laser gyroscope using a diode-pumped half-vertical-cavity semiconductor-emitting laser structure as a gain medium. Thanks to the control of mode competition by an active feedback loop, we observe a beat signal from recombined beams that has a frequency proportional to the rotation rate as predicted by the Sagnac effect. This promising result opens new perspectives for rotation sensing.

Jean-Paul Pocholle

Papers

Mode-Coupling Control in Resonant Devices: Application to Solid-State Ring Lasers

Modelling of the erbium-ytterbium laser.

Power lasers pumped by laser diodes

Miniature optical source

Single-frequency external-cavity semiconductor ring-laser gyroscope