Abstract

With this eyepiece the plane-polarization in a beam of light is compensated by means of a thin, plane-parallel plate of celluloid tilted at the proper angle. To ascertain if the compensation is complete a detector consisting of a quartz plate and a second tiltable plate of celluloid is used in combination with a Savart plate and a nicol or Wollaston prism. The biquartz plate consists of two plates of quartz cut normal to the optic axis, the one of dextrogyre and the second of laevogyre quartz, mounted side by side with polished junction faces. The thickness of the quartz plates is such (1.76 mm) that for mercury green light of wavelength 5461A the rotation is ±45°. An incident plane-polarized beam is divided into two beams by the biquartz plate; the plane of vibration of the beam emerging from the first half of the plate is normal to that of the second beam. The tiltable plate of the detector is mounted above the biquartz plate and has its axis of rotation in the plane of vibration of the wave emerging from one of the biquartz plate halves. By means of this second plate a small amount of polarization can be added to, or subtracted from the polarization in the transmitted beams. The Savart plate and analyzing prism serve to detect the presence of plane-polarized light in the beam. With the aid of this eyepiece the amount of plane-polarization can be determined, for low percentages, to one-fifth of one percent. The eyepiece has been used chiefly in the measurement of the percentage plane-polarization in light reflected by different parts of the moon’s surface and by terrestrial materials; also for the measurement of sky polarization and in metallographic work.

PDF Article

References

  • View by:
  • |
  • |

  1. D. Brewster, Edinburgh Trans. 9, 148 (1819); F. Savart, Pogg. Ann. 49, 292 (1840).
  2. J. Koenigsberger, Centralblatt f. Min., Geol, u. Paläon., 195–197 (1901); 565–569, 597–605 (1908); 245–250 (1909); 712–713 (1910).
  3. B. Lyot, Recherches sur la polarisation de la lumière des planèteset de quelques substances terrestres. Observatoire de Paris (section de Meudon) 12–15 (1929).
  4. For the preparation of mounted celluloid films the following method has been found satisfactory: A solution of celluloid in amylacetate or glacial acetic acid is poured over the clean surface of a piece of plate glass about 10 cm square; this is then set on edge, and the excess celluloid solution is allowed to drain off. The film remaining on the glass is thin, but it should not be so thin that it shows Newton interference colors. The film is allowed to dry over night. The brass annular ring is then placed with its flat mounting surface on the film and a small quantity of the celluloid solution is spread around the outer edge of the ring and permitted to dry for several hours; the celluloid film is then cut with a sharp knife edge drawn around the outside of the mounting ring. Water is now flowed around the cut and is forced by capillarity between the plate and film, thus gradually releasing the film from the glass plate. The celluloid film thus attached to the ring mount is quite flat and is not strained, as it may be if the film is first stripped from the glass and then mounted on the ring. If two parallel films are desired a second film may be mounted in the same manner on the opposite side of the ring.
  5. See reference 3, pp. 12–13.
  6. F. E. Wright, Am. J. Sci. (IV) 26, 377–378 (1908).
  7. See reference 3, pp. 21–23.
  8. F. E. Wright, The Transmission of Light Through Inactive Crystal Plates, with Special Reference to Observations in Convergent Polarized Light, Am. J. Sci. (IV) 19, 157–211 (1911).

Brewster, D.

D. Brewster, Edinburgh Trans. 9, 148 (1819); F. Savart, Pogg. Ann. 49, 292 (1840).

Koenigsberger, J.

J. Koenigsberger, Centralblatt f. Min., Geol, u. Paläon., 195–197 (1901); 565–569, 597–605 (1908); 245–250 (1909); 712–713 (1910).

Lyot, B.

B. Lyot, Recherches sur la polarisation de la lumière des planèteset de quelques substances terrestres. Observatoire de Paris (section de Meudon) 12–15 (1929).

Wright, F. E.

F. E. Wright, Am. J. Sci. (IV) 26, 377–378 (1908).

F. E. Wright, The Transmission of Light Through Inactive Crystal Plates, with Special Reference to Observations in Convergent Polarized Light, Am. J. Sci. (IV) 19, 157–211 (1911).

Other (8)

D. Brewster, Edinburgh Trans. 9, 148 (1819); F. Savart, Pogg. Ann. 49, 292 (1840).

J. Koenigsberger, Centralblatt f. Min., Geol, u. Paläon., 195–197 (1901); 565–569, 597–605 (1908); 245–250 (1909); 712–713 (1910).

B. Lyot, Recherches sur la polarisation de la lumière des planèteset de quelques substances terrestres. Observatoire de Paris (section de Meudon) 12–15 (1929).

For the preparation of mounted celluloid films the following method has been found satisfactory: A solution of celluloid in amylacetate or glacial acetic acid is poured over the clean surface of a piece of plate glass about 10 cm square; this is then set on edge, and the excess celluloid solution is allowed to drain off. The film remaining on the glass is thin, but it should not be so thin that it shows Newton interference colors. The film is allowed to dry over night. The brass annular ring is then placed with its flat mounting surface on the film and a small quantity of the celluloid solution is spread around the outer edge of the ring and permitted to dry for several hours; the celluloid film is then cut with a sharp knife edge drawn around the outside of the mounting ring. Water is now flowed around the cut and is forced by capillarity between the plate and film, thus gradually releasing the film from the glass plate. The celluloid film thus attached to the ring mount is quite flat and is not strained, as it may be if the film is first stripped from the glass and then mounted on the ring. If two parallel films are desired a second film may be mounted in the same manner on the opposite side of the ring.

See reference 3, pp. 12–13.

F. E. Wright, Am. J. Sci. (IV) 26, 377–378 (1908).

See reference 3, pp. 21–23.

F. E. Wright, The Transmission of Light Through Inactive Crystal Plates, with Special Reference to Observations in Convergent Polarized Light, Am. J. Sci. (IV) 19, 157–211 (1911).

Cited By

OSA participates in CrossRef's Cited-By Linking service. Citing articles from OSA journals and other participating publishers are listed here.

Alert me when this article is cited.