Michelson optics

In a solid-liquid-vapour system where the solid substrate is opaque and less reflective than the liquid surface, Michelson optics (i.e. those based on the Michelson interferometer) can be employed. In this case, the light reflected from a flat optical mirror is superimposed on to the light reflected from the liquid drop surface. If the underlying solid phase is transparent, other constellations of interferometry can be applied (49). 

In an industrial-design FTIR spectrometer, a modified form of the G enzel interferometer is utilized.A geometric displacement of the moving mirrors by one unit produces four units of optical path difference (compared with two units of optical difference for a Michelson type interferometer). The modified Genzel design reduces the time required to scan a spectrum and further reduces the noise effects asstxiated with the longer mirror translation of most interferometers. 

In the mid-IR, routine infrared spectroscopy nowadays almost exclusively uses Fourier-transform (FT) spectrometers. This principle is a standard method in modem analytical chemistry45. Although some efforts have been made to design ultra-compact FT-IR spectrometers for use under real-world conditions, standard systems are still too bulky for many applications. A new approach is the use of micro-fabrication techniques. As an example for this technology, a miniature single-pass Fourier transform spectrometer integrated on a 10 x 5 cm optical bench has been demonstrated to be feasible. Based upon a classical Michelson interferometer design, all... 

This interferometric dilatometer consists of a rather simple and small Michelson interferometer, in which the two arms are parallel, and of a 4He cryostat, in which the sample to be measured is hold. The sample is cooled to 4 K, and data are taken during the warm up of the cryostat. The optical path difference between the two arms depends on the sample length hence a variation of the sample length determines an interference signal. The Michelson interferometer consists of a He-Ne stabilized laser (A = 0.6328 xm), two cube corner prisms, a beam splitter, three mirrors and a silicon photodiode detector placed in the focal plane of a 25 mm focal length biconvex lens (see Fig. 13.1). 

Infrared spectra were taken with a Michelson-Genzel type FTIR instrument (IR/98, IBM Instruments, Inc.) equipped with a liquid nitrogen cooled HgCdTe detector. The optical attachment arrangement is shown in Fig. 2-14. The infrared radiation was p-polarized using ERS-5 wire grid polarizer. 

Figure 10.11—Optical arrangement of a Fourier transform IR spectrometer, a) A 90c Michelson interferometer including the details of the beam splitter (expanded view) b) optical diagram of a single beam spectrometer (based on a Nicolet model). A weak intensity HeNe laser (632.8 nm) is used as an internal standard to measure precisely the position of the moving mirror using an interference method (a simple sinusoidal interferogram caused by the laser is produced within the device). According to the Nyquist theorem, at least two points per period are needed to calculate the wavelength within the given spectrum.

Albert Michelson developed the interferometer about 1880 and conducted the Michelson-Morley experiment in 1887, in which it was found that the speed of light is independent of the motion of the source and the observer, this crucial experiment led Einstein to the theory of relativity. Michelson also used the interferometer to create the predecessor of today s length standard based on the wavelength of light. He received the Nobel Prize in 1907 for precision optical instruments and the spectroscopic and metrological investigations carried out with their aid. ... 

In 1926 the Michelson-Gale experiment was confirmed by Pogany [14], who determined the surface velocity of the rotating earth by a closed optical... 

Naturally this coincidence does not mean that the geometric optics added to the classical physics could be used for the exact description of the light propagation since the Michelson-Morley experiment refuted its validity forever. It is evident that there are possible new mathematical definitions for c+ and c instead of the ordinary speed addition mle of the classical physics seen in Eqs. (9) and (11). These can be compatible with the experimental results as well. 

The maximum optical throughput for a Michelson interferometer, 0 is given by max 6... 

---