Abstract

During the course of the investigation on the primary standard of light at the National Research Council of Canada [ Sanders and Jones, J. Opt. Soc. Am. 52, 731 ( 1962)] it was found that the illuminance distribution across the image of the opening of the blackbody radiator was not uniform. The nonuniformity was attributed to diffraction caused by the imaging lens. An experimental check on this assumption has been carried out in which the blackbody radiator was simulated by a source consisting of a projection lamp, condenser lens, and an integrating sphere, which provides a uniform luminance. The nonuniformity of illuminance across the image, as well as the decrease of illuminance in the center, was measured using two different lenses. The latter follows the prediction in accordance with the diffraction theory to within 0.1%. If stray light is considered the agreement is further improved. A method is discussed which eliminates errors of the primary standard of light caused by diffraction.

© 1964 Optical Society of America

Full Article  |  PDF Article

References

  • View by:
  • |
  • |
  • |

  1. Proces-Verbaux Séances Comité Inter-Natl. Poids Mesures 20, 119 (1946).
  2. C. L. Sanders and O. C. Jones, J. Opt. Soc. Am. 52, 731 (1962).
    [CrossRef]
  3. W. Budde, Appl. Opt. 3, 69 (1964).
    [CrossRef]

1964 (1)

1962 (1)

1946 (1)

Proces-Verbaux Séances Comité Inter-Natl. Poids Mesures 20, 119 (1946).

Appl. Opt. (1)

J. Opt. Soc. Am. (1)

Proces-Verbaux Séances Comité Inter-Natl. Poids Mesures (1)

Proces-Verbaux Séances Comité Inter-Natl. Poids Mesures 20, 119 (1946).

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.


Figures (6)

Fig. 1
Fig. 1

Arrangement for the measurement of both the illuminance distribution of the image and the change of illuminance at the center of the image.

Fig. 2
Fig. 2

Method for the measurement of uniformity and diffusibility of the source.

Fig. 3
Fig. 3

Uniformity of luminance on the baffle. C is the center, and each figure indicates the relative deviation of luminance at that point from that at the center, multiplied by 10 000.

Fig. 4
Fig. 4

Comparison of the spectral distributions of the outputs of the receivers. Curve 1. (Spectral energy density of the primary standard of light)×(Vλ). Curve 2. (Spectral energy density of the present source)×(spectral sensitivity of the present receiver). Curve 3. (Curve 2)×(spectral transmittance of the blue filter). Curve 4. (Curve 2)×(spectral transmittance of the orange filter).

Fig. 5
Fig. 5

Illuminance distribution of images projected by Lens No. 1 at a distance of 3 m. r0 is the radius of the opening, ρ0 the radius of the image, both in mm. Curves are normalized so that the illuminance at the center is unity. Continuous lines give the distribution for r (radius of the lens aperture)=6.5 mm, while dotted lines give the distribution for r=10 mm.

Fig. 6
Fig. 6

A method of measuring the transmittance of the lens with the same effective diffraction as in the measurement of the primary standard. The transmittance (T) is given as the ratio of the reading of the receiver in the case of (a) to the reading in (b). The opening of the source, the lens aperture, the receiver, and the distance (D2) must be identical with those used in the measurement of the primary standard.

Tables (6)

Tables Icon

Table I Decrease of the average illuminance for large receiver apertures (Lens No. 1).

Tables Icon

Table II Decrease of illuminance (Lens No. 1).

Tables Icon

Table III Decrease of illuminance (Lens No. 1).

Tables Icon

Table IV Decrease of illuminance (Lens No. 2).

Tables Icon

Table V Decrease of illuminance (Lens No. 2).

Tables Icon

Table VI Decrease of illuminance (Lens No. 2).

Equations (3)

Equations on this page are rendered with MathJax. Learn more.

N = ( π r 2 / D 2 2 ) T B [ 1 - J 0 2 ( V 0 ) - J 1 2 ( V 0 ) ] ,
J 0 2 ( V 0 ) + J 1 2 ( V 0 ) = ( N - N ) / N .
n = λ D 2 / π 2 r ρ 0 .