Abstract

For a spatially extended light source of uniform cross section, such as a Raman tube, the most favorable focal length of the condensing lens is F = hf/(bs), where 2h is the extension of the source in the direction of the spectrograph slit, f the focal length of the collimator lens, 2b the height of the prism, and 2s the length of the slit. With such a condensing lens, placed a distance of (h+s)f/(bs) from the slit, the greatest possible length, lmax = h2f/bs, of the source is fully effective in filling the spectrograph. This was proved by the writer a number of years ago under the assumption that hs. Often, however, the small amount of the scattering material available necessitates the use of a Raman tube of small cross section. The case hs is therefore investigated here. It is shown that the theorem stated holds also in this case. However, in order that the full amount of light may enter the spectrograph, some of the scattered light must pass out through the wall of the Raman tube and pass through the condensing lens at a distance from the center which is greater than the radius of the Raman tube. This has certain disadvantages. It is therefore often advantageous to make h=s, in which case the maximum effective length of the Raman tube can be attained more satisfactorily by using a condensing lens of focal length sf/(b+s) immediately in front of the slit and placing the front end of the Raman tube right against the lens.

© 1947 Optical Society of America

Full Article  |  PDF Article
OSA Recommended Articles
The Measurement of the Intensity Ratios of Spectral Lines with Electron Multiplier Photo-Tubes

K. G. Kessler and R. A. Wolfe
J. Opt. Soc. Am. 37(3) 133-144 (1947)

References

You do not have subscription access to this journal. Citation lists with outbound citation links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Cited By

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Figures (2)

You do not have subscription access to this journal. Figure files are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Tables (3)

You do not have subscription access to this journal. Article tables are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Equations (36)

You do not have subscription access to this journal. Equations are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription