Concave mirror spherical

A spherical concave mirror of radius R — CP = CQ reflects an object at O (mirror-object distance OP = u) into image at / (mirror-image distance IP= v). If object moves to infinity (u = oo), then all rays from that object will converge at the principal focus point F f—FP = (1/2) CP—RI2] that is, the principal focal length f is half of the radius of curvature. 

The most important and unique part of a Fourier transform microwave spectrometer is the Fabry Perot cavity. A fairly complete description of the principles has been given by Balle and Flygare [14] and we here summarise the main aspects, with the aid of figure 10.19. We use the cavity built by Balle and Flygare as a typical example. It is formed by two parallel, spherical concave mirrors made from solid aluminium. The mirrors are 36 cm in diameter, have a radius of curvature (R) of 84 cm, and are situated... 

Fig. 3.5-10 c shows another sample arrangement which makes use of a fiber-optical connection from the laser to the sample and back to the spectrometer. It is specially designed for the scanning of surface layers, e.g., of precious prints or paintings. The half spheric concave mirror reflects the portion of exciting radiation and Raman radiation back to the sample which has been. scattered by the sample and is not collected by the optical fiber. Thus the mirror as a component of a multiple reflection system enhances the observed intensity of the Raman lines by a factor of 2 to 8, depending on the properties of the sample. 

Figure 9.12 Monochromator gratings, (a) Ebert assembly incorporating a single concave spherical mirror M3. Able to compensate for aberrations this monochromator gives excellent image quality, (b) Of similar design to Ebert the Czerny-Turner assembly contains two spherical concave mirrors Mj and M4. (c) The concave grating in this design permits hoth dispersion and focussing of the radiation. The spectral bandwidth of these monochromators depends upon the width of the entrance and the exit Fj slits, respectively.

Euclid, about 300 B.C., treated mathematically the size relations of the object and the image for plane and spherical mirrors. He located the focal point of concave mirrors and laid a foundation for the study of convergence and divergence of light beams reflected from mirrors. About 100 B.C., Hero presumably laid the basis of the law concerning the equality of the angles of... 

The first concave mirror in Figure 20 is not essential, but in many experiments the energy density is increased by placing the experimental cell in a spherical concentric Fabry-Perot cavity. The windows of the experimental cell must be tilted at the Brewster angle to reduce the losses in the cavity. The length of this cavity is piezoelectrically locked on the Laser frequency, to maximize the signal transmitted throug it. 

The Offiier 1 1 reimager is aa off-ads, imobscored, reflective, all-spherical system consisting of two mirrors a large concave mirror, and a small convex mirror. It is free from all primary aberrations (Offiier 1975 Kingslake 1978). 

M3, which compensates for aberrations and yields an excellent quality of image b) Czerny-Turner design, similar in conception, incorporating two spherical mirrors. M and jf/4 c) design with a concave grating (7( allowing simultaneous dispersion and focusing of the radiation. The spectral bandwidth of these monochromators depends on the width of the entrance and exit slits, F, and F2-... 

In an Ebert monochromator the entrance slit and exit slit are either side of the grating and a single concave spherical mirror is used as a collimating and focusing element (Figure 125). Wavelength scanning and selection of a... 

Figure 4.25. Optical diagram of DRIFTS accessory (1) flat mirror (50 x 50 mm), (2) flat mirror (70 X 70 cm), (3) concave spherical reflector, and (4) sample cell D = diffuse reflection S = specular reflection. Dashed lines show optical path of diffuse reflection. Solid bold line shows optical path of specular reflection. Reprinted, by permission, from B. Li and R. D. Gonzalez, Appl. Spectrosc. 52, 1488-1491 (1998), p. 1489, Fig. 1. Copyright 1998 Society for Applied Spectroscopy.

---