Atsushi Kikkawa

Photoelectric pulse interval distribution of gaussian-lorentzian light

Abstract The time interval distribution of two successive photoelectric pulses depends not only upon the spectral linewidth but also on the correlation factor. The distribution is derived in the case of gaussian-lorentzian light under the condition of a markovian process and is also applied to the analysis of the counting loss of a circuit with dead time, from which information on the spectral linewidth is obtained. The theoretical counting loss is compared with the experimental one.

Spectroscopy of Light Scattered by Suspended Charged Particles

Two spectroscopic techniques of the Rayleigh scattered light have been investigated. One investigation is on a method to measure the Rayleigh linewidth precisely. From the measurements it is found that the linewidth of the scattered light by the polystyrene latex particles in the buffer solution is significantly different from that obtained from the Einstein-Stokes relation. The other investigation is on an application of the spectroscopic method for the detection of the electrophoretic analysis. From the investigation it is found that the Rayleigh scattered spectral line shows the Doppler shift by the electrophoretic movement of the particle and that the electrophoretic velocity can be measured in real time.

Statistics of photoelectric pulses for Gaussian-Lorentzian light

The practical treatment of statistics for Gaussian-Lorentzian light is studied theoretically and experimentally by using the time interval distribution of photoelectric pulses, which is derived in two approaches that are based on Markovian processes and the generating function of photon counting statistics, taking the experimental conditions into account. The limits of the validity of the Markovian assumption are made clear. In arbitrary light intensity it is valid experimentally to employ the practical generating function of photon counting distribution expressed as the product of an ideal generating function and a Poissonian one.

The spectral profile of light scattered by particles in electrophoretic movement

Abstract The electrophoretic movements of polystyrene latex particles suspended in water and in electrolyte solutions have been investigated with an optical beating technique. When two kinds of particles in water move in the presence of an external electric field, it is observed that the laser light scattered by these particles exhibits a shifted spectrum with a single peak profile, even if the electrophoretic mobilities of the two kinds of particles are different to each other. However, when these particles are suspended in an electrolyte solution, two separate spectral lines are observed which correspond to the velocity of each kind of particles.

Two-fold time interval distribution of photoelectric pulses of gaussian-lorentzian light

Abstract The two-fold time interval distribution which is the probability distribution of the time interval between the first and the third one of successive photoelectric pulses is derived from the generating function of the photon counting distribution of gaussian-lorentzian light under the condition of measurements for the purpose of spectroscopy of Rayleigh scattered light. The time interval measurement of photoelectric pulses is made by using a digitalized electric system. Experimental results show good agreement with the theoretical ones.

Dead-Time Losses of Multichannelized Delayed Coincidence Spectrometer

Counting losses of multichannelized delay lines are calculated and a delayed coincidence spectrometer is designed. As the results of the calculation, 10 delay lines are prepared as a multichannelized delay line in the spectrometer. In order to set the delay times of 10 delay lines exactly the same, a digitally controlled system is employed. The experimental results of counting losses and delayed coincidence rates show good agreements with the calculated results. According to the investigation of the counting loss of the multichannelized spectrometer, it is noted that the counting efficiency of the 10 channelized spectrometer is about 400 times better than that of a single channel spectrometer.

Statistical Properties of Gaussian-Lorentzian Light and Dead Time Loss of Photon-Counting System

The counting loss of a circuit with a dead time is increased according to the input counting rate and the dead time as well as the parameters of the statistical distribution of input pulses in photocounting of the Gaussian-Lorentzian light. Relationship between the spectral linewidth of the incident light and the counting loss is investigated theoretically and experimentally, when a single channel dead time system is used. Moreover, a multichannelized dead time system is employed by using a scaling technique. It is recognized that the spectral linewidth can be determined from measurement of the counting loss.

A Delayed Coincidence Spectrometer and Spectral Line Profiles of Scattered Lights

A delayed coincidence spectrometer was designed, and a spectrum of laser light scattered by spherical particles suspended in water was acculatly measured with the spectrometer. The light scattered by spherical particles of uniform size had a single Lorentzian spectrum. When a spectrum of scattered light from a mixture of these particles of two different sizes was acculatly measured, the concentration ratio of the two types of particles could be determined from the linewidth observation.

Determination of Random Component in Delayed Coincidence Spectroscopy

In order to determine a spectral line-width with a delayed coincidence spectrometer, the random component must be measured accurately. For this purpose, the mean frequency method is investigated. The random component measured by this method is equal to the product of the gate time of counting and the mean square frequency of input pulses. In this method, the gate time of the spectrometer must be set accurately and, therefore, is determined by a digital circuit. The mean frequency method is employed for the measurement of scattered light. It is found that the bunching component can be determined in detail and that the spectral line-width of a single Gaussian light can be measured accurately and promptly.

Statistical Distributions of Photoelectric and Dark Pulses

Spectral linewidth of incidence light can be found by statistical distribution of photoelectric pulses.However, a detector has dark pulses and dark pulses distort the statistical properties of the distribution.When dark pulses have Poissonian distribution, the linewidth of incident light can be known by taking into account dark pulse contribution.In this work, statistical properties of photoelectric pulses have been investigated after the investigation on the dark pulses.It has been found that the distributions of dark pulses, the laser light, and the thermal light are exactly Poissonian.According to the fact that dark pulses had Poissonian distribution, the spectral linewidth of sacttered laser light has been determined by using the departure from Poissonian distribution.