Abstract

The construction of optical filters, which are required to have optical properties well defined over wide spectral regions, demands the use of multilayer designs in which there are no simple relationships between the thicknesses of the layers. There are considerable difficulties in the manufacture of such multilayers. First, we must be able to reproduce, sufficiently accurately, the indices of refraction that have been used in the theoretical design. Then we must be able to control the optical thicknesses of each layer, which necessitates measurement of the optical properties of the multilayer during deposition. The apparatus described consists of a minicomputer coupled to a rapid-scanning spectrometer that continuously measures the spectral profile during deposition of each layer. The precise measurement of the evolution of the optical properties during actual construction of a filter allows us to control layer thickness with very good accuracy. The technique is demonstrated in the monitoring of a beam splitter made of a few layers.

© 1979 Optical Society of America

Full Article  |  PDF Article

References

  • View by:
  • |
  • |
  • |

  1. B. Vidal, A. Fornier, E. Pelletier, Appl. Opt. 17, 1038 (1978).
    [CrossRef] [PubMed]
  2. J. P. Borgogno, E. Pelletier, J. Opt. Soc. Am. 68, 964 (1978).
    [CrossRef]
  3. Nine articles on rapid-scan spectroscopy: Appl. Opt. 7, 2155 (1968).
    [PubMed]
  4. R. Higara, M. Sugawara, S. Ogura, S. Amano, J. Appl. Phys. Suppl. II, 689 (1974).
  5. E. Pelletier, P. Roche, B. Vidal, Nouv. Rev. Opt. Appl. 7, 353 (1976).
    [CrossRef]
  6. B. Vidal, E. Pelletier, Appl. Opt. 18, 3857 (1979).

1979 (1)

1978 (2)

1976 (1)

E. Pelletier, P. Roche, B. Vidal, Nouv. Rev. Opt. Appl. 7, 353 (1976).
[CrossRef]

1974 (1)

R. Higara, M. Sugawara, S. Ogura, S. Amano, J. Appl. Phys. Suppl. II, 689 (1974).

1968 (1)

Nine articles on rapid-scan spectroscopy: Appl. Opt. 7, 2155 (1968).
[PubMed]

Amano, S.

R. Higara, M. Sugawara, S. Ogura, S. Amano, J. Appl. Phys. Suppl. II, 689 (1974).

Borgogno, J. P.

Fornier, A.

Higara, R.

R. Higara, M. Sugawara, S. Ogura, S. Amano, J. Appl. Phys. Suppl. II, 689 (1974).

Ogura, S.

R. Higara, M. Sugawara, S. Ogura, S. Amano, J. Appl. Phys. Suppl. II, 689 (1974).

Pelletier, E.

Roche, P.

E. Pelletier, P. Roche, B. Vidal, Nouv. Rev. Opt. Appl. 7, 353 (1976).
[CrossRef]

Sugawara, M.

R. Higara, M. Sugawara, S. Ogura, S. Amano, J. Appl. Phys. Suppl. II, 689 (1974).

Vidal, B.

Appl. Opt. (1)

Nine articles on rapid-scan spectroscopy: Appl. Opt. 7, 2155 (1968).
[PubMed]

Appl. Opt. (2)

J. Appl. Phys. Suppl. II (1)

R. Higara, M. Sugawara, S. Ogura, S. Amano, J. Appl. Phys. Suppl. II, 689 (1974).

J. Opt. Soc. Am. (1)

Nouv. Rev. Opt. Appl. (1)

E. Pelletier, P. Roche, B. Vidal, Nouv. Rev. Opt. Appl. 7, 353 (1976).
[CrossRef]

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 (9)

Fig. 1
Fig. 1

(a) Monitoring system for transmittance measurements. (b) Monitoring system for transmittance measurements using an array of silicon photodiodes.

Fig. 2
Fig. 2

Computed evolution of spectral profile during construction of the beam splitter of Table I. Evolution of the spectral transmittance of the coating during deposition of the layers is indicated in this diagram. The profile has been calculated and traced at thickness intervals of 1/30th of each layer. For convenience of comparison, they are displaced equally along the thickness axis. (It should be noted that the thickness interval varies with the total thickness of the appropriate layer.)

Fig. 3
Fig. 3

Simulated evolution of the merit function f1 [see Eq. (1)] during control of layer 1.

Fig. 4
Fig. 4

Simulated evolution of the merit function f2 [see Eq. (1)] during control of layer 2 when the error in the first layer is negligible.

Fig. 5
Fig. 5

Simulated evolution of the merit function f3 [see Eq. (1)1 during control of layer 3 when the errors in the two first layers are negligible.

Fig. 6
Fig. 6

Measurement of the evolution of the merit function during deposition of the first layer. Deposition is terminated when the value passes through a minimum near zero.

Fig. 7
Fig. 7

Measurement of the evolution of the merit function during deposition of layer 2.

Fig. 8
Fig. 8

Measurement of the evolution of the merit function during deposition of layer 3.

Fig. 9
Fig. 9

Transmittance vs wavelength. Beam splitter, 3 layers (ZnS and NaAlF6). The difference between the expected profile and the experimental result is due to the intentional overshoot of the thickness of layer number 1: —calculated filter; + experimental result.

Tables (2)

Tables Icon

Table I Design of a Beam Splitter (Normal Incidence) on a Substrate of Index 1.52

Tables Icon

Table II Control Program of the Production of a Three-Layer Beam Splitter

Equations (9)

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

f i ( e ) = λ 1 λ 2 T i ( λ , e i ) - T i ( λ , e ) d λ ,
φ 0 ( λ ) = φ A ( λ ) T r T 0 1 - R r R 0 ,
φ i ( λ ) = φ A ( λ ) T r T i 1 - R r R i .
φ i ( λ ) φ 0 ( λ ) = T i T 0 · ( 1 - R r R 0 ) ( 1 - R r R i ) .
f i ( e ) = λ 1 λ 2 T i ( λ , e i ) - T i ( λ , e ) d λ .
f i ( e ) = λ 1 λ 2 | τ i th - φ i ( λ ) φ 0 ( λ ) | d λ ,
τ i th = T i ( λ , e i ) T 0 · 1 - R r R 0 1 - R r R i ( λ , e i ) .
f i = J = 1 100 | τ i th ( λ j ) - φ i ( λ j ) φ 0 ( λ j ) | .
f i = J = 1 10 Ω i , J | τ i th ( λ J ) - φ i ( λ J ) φ 0 ( λ J ) | .

Metrics