Microanalysis of Brownian Particles and Real-Time Nanometer Vibrometry with a Laser-Diode-Pumped Self-Mixing Thin-Slice Solid-State Laser

Abstract

A comprehensive analysis of gened relativistic spacetimes which admit a shearfree, irrotational and geodesic time-like coogruence is presented. The equations governing the models for a gened energy-momentum tensor are wrilten down. Coordinates in which the metric of such spacetimes takes on a simplified form are established. The general subwses of 'zero anisotropic stress', 'zero heat-flux vector' and 'two-component Ruids' are investigated. In particular, perfect-fluid Friedmann-Robertson-Walker models and spatially homogeneous models are discussed. Models with a variety of physically relevant energy-momentum tensors are considered. Anisowopic fluid models and viscous fluid models with heat conduction are examined. Also. models with B perfect Ruid plus a magnetic field or with pure radiation. and models with two non-collinw perfect fluids (satisfying a variety of physical conditions) are inwtigated. In particular. models with a (single) perfect Ruid which is tilting with respect to the shem-free, vorticity-free and acceleration-free time-like congruence are discussed.PACS numbers: 0420J. 9880H

Self-Mixing Thin-Slice Solid-State Laser Metrology

“…, carrier frequency) by using LabView software on a personal computer, as mentioned in 4.1.1. The measured vibration amplitude was confirmed to coincide with those measured with a capacitive displacement sensor [39]. The cross talk among three channels was completely eliminated by tuning the filter bandwidth of the FM-demodulator circuit around the carrier frequency.…”

“…Fitting curves are shown by red lines (reprinted with permission from [39]; © 2006, The Japan Society of Applied Physics).…”

Polarization Properties of Laser-Diode-Pumped Microchip Nd:YAG Ceramic Lasers

“…On the other hand, singlefrequency linearly polarized emissions that were free from dynamic instabilities were achieved in microcrystalline Nd:YAG ceramic samples, whose average grain size was a few micrometers. In this section, we describe the effect of average grain size on transverse lasing patterns, detailed oscillation spectra, and polarization properties of LD-pumped Nd:YAG ceramic lasers to address the problems associated with making highly coherent miniature ceramic lasers possessing high beam quality and lasing frequency purity for applications besides high-power operation, e.g., laser metrology (Sudo et al 2006). …”

Micro Particle Sizing Using Hilbert Transform Time Domain Signal Analysis Method in Self-Mixing Interferometry

“…They demonstrated the possibility of measuring particle sizes ranging from 20 nm to 200 nm. Sudo et al also successfully implemented particle sizing measurement using the DS method, where the particle dimension and concentration were quantitatively characterized using the Lorentz fitting of the power spectrum of the SMI signal from polystyrene particles of diameters ranging from 20 nm to 500 nm [8,9]. They also reported a forward experimental work by means of an acoustic-optical modulated self-mixing laser metrology for the accurate measurement of diffusion constants [10][11][12][13].…”