We describe a new and highly effective optical frequency discriminator and laser stabilization system based on signals reflected from a stable Fabry-Perot reference interferometer. High sensitivity for detection of resonance information is achieved by optical heterodyne detection with sidebands produced by rf phase modulation. Physical, optical, and electronic aspects of this discriminator/laser frequency stabilization system are considered in detail. We show that a high-speed domain exists in which the system responds to the phase (rather than frequency) change of the laser; thus with suitable design the servo loop bandwidth is not limited by the cavity response time. We report diagnostic experiments in which a dye laser and gas laser were independently locked to one stable cavity. Because of the precautions employed, the observed sub-100 Hz beat line width shows that the lasers were this stable. Applications of this system of laser stabilization include precision laser spectroscopy and interferometric gravity-wave detectors.

http://jila1.nickersonm.com/papers/Laser%20Phase%20and%20Frequency%20Stabilization%20Using%20an%20Optical%20Resonator.pdf

Laser phase and frequency stabilization using an optical resonator

Review of the present status of optical fiber sensors

We first provide an overview of 3-D shape measurement us- ing various optical methods. Then we focus on structured light tech- niques where various optical configurations, image acquisition tech- niques, data postprocessing and analysis methods and advantages and limitations are presented. Several industrial application examples are presented. Important areas requiring further R&D are discussed. Finally, a comprehensive bibliography on 3-D shape measurement is included, although it is not intended to be exhaustive. © 2000 Society of Photo-Optical Instrumentation Engineers. (S0091-3286(00)00101-X)

Overview of three-dimensional shape measurement using optical methods

Publisher Summary This chapter describes the coherent population trapping in laser spectroscopy. Coherent population trapping may be also described as the pumping of the atomic system in a particular state, the coherent superposition of the atomic states, which is a nonabsorbing state. The exciting radiation creates an atomic coherence, such that the atom's evolution is prepared exactly out of phase with the incoming radiation and no absorption takes place. The chapter discusses the basic properties of an atomic system prepared with the coherent population-trapping superposition of states and outlines experimental observations concerned with the establishment of coherent trapping in different discrete systems. The chapter also discusses the theoretical and experimental aspects of trapping that involve states of the continuum and reviews the theoretical and experimental features associated with coherent population trapping in laser cooling, adiabatic transfer, lasing without inversion, pulse matching, and photon statistics. The theoretical aspect of coherent population trapping created by spontaneous emission is also discussed in the chapter.

Coherent Population Trapping in Laser Spectroscopy

Microwave photonics with superconducting quantum circuits

1. Introduction.- 2. Elements of the Theory of Resonant Interaction of a Laser Field and Gas.- 3. Narrow Saturation Resonances on Doppler-Broadened Transition.- 4. Narrow Resonances of Two-Photon Transitions Without Doppler Broadening.- 5. Nonlinear Resonances on Coupled Doppler-Broadened Transitions.- 6. Narrow Nonlinear Resonances in Spectroscopy.- 7. Nonlinear Atomic Laser Spectroscopy.- 8. Nonlinear Molecular Laser Spectroscopy.- 9. Nonlinear Narrow Resonances in Quantum Electronics.- 10. Narrow Nonlinear Resonances in Experimental Physics.- 11. Conclusion.- Author Index.

Nonlinear Laser Spectroscopy

We report the observation of optical amplification in a two-level atomic system driven by a strong, resonant field. By exciting an atomic beam of two-level sodium atoms simultaneously with a strong, fixed-frequency driving field and a weak, tunable, probe field, we have measured the absorption (amplification) line-shape function for several values of driving field strength. In addition, we have verified theoretical predictions that higher amplification is obtained when the strong field is detuned from exact resonance.

Observation of Amplification in a Strongly Driven Two-Level Atomic System at Optical Frequencies

A stimulated Brillouin fiber ring laser with a spectral width of 2 kHz and an intrinsic linewidth of less than 30 Hz has been demonstrated. Applications of such a laser include laser linewidth narrowing, microwave frequency generation, high-rate amplitude modulation, and optical inertial rotation sensing.

Narrow-linewidth stimulated Brillouin fiber laser and applications

Measurements of the spectrum of resonance fluorescence induced by a monochromatic laser field in an atomic beam of sodium have been made over a wide range of laser intensities for both on- and off-resonance excitation. The spectra are consistent with theoretical calculations first made by Mollow.

Investigation of the Spectrum of Resonance Fluorescence Induced by a Monochromatic Field

A new method of measuring inertial rotation is presented. It is based on the use of a passive ring resonator as the rotation sensing element and an external laser for measuring the difference between the clockwise and counterclockwise lengths of the resonator. Preliminary performance data is included.

Shaoul Ezekiel

Papers

Nonlinear Laser Spectroscopy

Observation of Amplification in a Strongly Driven Two-Level Atomic System at Optical Frequencies

Narrow-linewidth stimulated Brillouin fiber laser and applications

Investigation of the Spectrum of Resonance Fluorescence Induced by a Monochromatic Field

Passive ring resonator laser gyroscope