Mirror drive

Vibration Vibration can be a major disruption and destractive influence for any form of instrumentation. FTIR is a special case because the fundamental measurement is vibration sensitive. Care must be taken to ensure that the mirror drive, and associated optics and components are immune to vibration. Note that mirror mounts, and even detector mounts can be a source of vibrational interference. From a more basic standpoint, constant vibration can work components loose, and so the extensive use of a screw bonding adhesives, is strongly recommended. 

However, it is to be noted that the Fourier transform integrals have infinite limits while the optical path differences are finite so modifications or approximations must be made. We will use the approximation of the limits between —L and + L where L is the maximum distance of the mirror drive. So... 

Figure 1. Diagram of a Michelson interferometer. Key l, unmodulated incident beam A, moving mirror B, stationary mirror E, modulated exit beam D, detector MD, mirror drive.

OQ should include backup and recovery, data archive and retrieval, security, system administration procedure verification, startup and shutdown, UPS continuity, communications loss and recovery, and systems redundancy challenges such as mirrored drives, secondary systems, and failsafe systems. 

Fig. 49. The Polytec FIR 30 Fourier spectrometer (No. 5c in Tables 2, 3, 4) Optical diagram (lower part) and the possibilities of using the sample chamber (upper half). M 2, M 3, M 5, M 6 plane mirrors M 1, M 4 paraboloid mirrors M 7 spherical mirror M8 elliptical mirror C Chopper S high pressure Hg-lamp BS beamsplitter D mirror drive IS Moird system G Golay detector S sample...

What length of mirror drive will provide a resolution of 0.1 Cm ... 

What length of mirror drive in a Michelson interferometer is required to produce... 

An Intel 8086 computer co-ordinates the overall sequence of operations, converting the outputs of the zoom and pan controls into the correct signals for the mirror drives, providing synchronisation pulses for line and frame scans, and controlling the overall scan speed. 

The effect of a drive mechanism that does not allow the plane of the moving mirror of the interferometer to maintain its angle relative to the plane of the beamsplitter is somewhat analogous to the effect of beam divergence discussed in Section 2.6. In the case of the poor mirror drive, however, an optical path difference is generated between the two extreme rays of the beam passing through the interferometer rather than a path difference between the extreme rays and the central ray. 

---