The interference microscope is an integration of microscope and interferometers, the shapes of which can be classified as (1) Michelson, (2) Mach-Zehnder, (3) cyclic and (4) common-path or polarization interferometer. After introducing general principles of two-beam interferometry, the author reviews the techniques of interference microscopy and the principles of various types of interference microscopes according to the above-mentioned classification. Some remarks are given on its future possibilities including the use of lasers.
A theoretical analysis of gas lenses is made. The equations of light rays in lens-like media are discussed. The ray trajectories in gas lenses having a square-law index variation are calculated and the path of helical light rays in such a medium is analyzed. The translation matrices of gas lenses are obtained and some discussion concerning these matrices is given. As examples of optical systems using gas lenses, a telescope and an optical transmission line consisting of gas lenses are analyzed.
A three-dimensional pattern display apparatus has been developed using a 5 inch X-Y oscilloscope as the displayer. The main point of the development consists of a new type of digital to analog converter in which reading of spot positions of extremely high precision is possible. The new digital-analog converter is specified by the following points: the maximum output is 10 volts, the zero level drift is within 10μV, the linearity is better than 0.1%, the response speed is faster than 1μ second after signal injection. The precise spot readers make this apparatus very convenient, being able to read X and Z coordinates of any designated spot in a pattern. This article shows a method to realize technically such display apparatus.
The behavior of a PN-photodiode and its dependence upon the biasing electric field are discussed theoretically by taking into consideration the hot electron mobility and the space charge effect in semiconductors. It is shown that the non-saturation photocurrent is directly proportional to the reverse bias field in the depletion-layer of the linear-graded junction diode. These theoretical results agree with our experimental results which were obtained using a ruby laser as the optical source. The photocurrent, reduction factors and transit phases, the latter two of which are a measure of the frequency response, are obtained in the case where light is incident parallel to the junction plane and the electric field is distributing parabolically in the depletion-layer. It is shown from this analysis that the parabolic field distribution gives smoother reduction profiles than a uniform field. The relation between the laser intensity and the optimum biasing electric field is given.
When an ultrasonic beam is incident on a platelike tank, consisting of two sheets of plane parallel plate glass with a thin liquid layer of acetic acid or carbon-disulfide between them, a kind of ultrasonic standing wave is formed in the liquid, if the angle of incidence is within a certain, region. The pattern of the waves can be observed by a comparatively simple method.
Multiple ruby laser pulses at regular time intervals of 1μ sec were obtained, with an external mirror oscillating at 1 Mc/sec. Using these pulses as a stroboscopic light source, high-speed photographs of the preliminary stage of dielectric breakdown in insulating oil were taken.