Deposition of gradient index coatings using coevaporation with r

Details Deposition of gradient index coatings using coevaporation with r Deposition of gradient index coatings using coevaporation with r

1987-03-20

1990-06-19

Arnold, Bruce Y.

350166, G02B 528

Patent

active

049347888

ABSTRACT:
A method of depositing an optical coating with a predetermined refractive index n and a thickness d, using a first source material having a refractive index n.sub.H greater than n and a known rate of deposition r.sub.H and a second source material having a refractive index n.sub.L less than n and a variable rate of deposition r.sub.L, requires calculating the deposition rate r.sub.L according to the equation ##EQU1## and depositing the first source material at the rate r.sub.H and the second source material at the rate r.sub.L for a time interval T=d/(r.sub.H +r.sub.L). A method of depositing a gradient index optical coating with a predetermined refractive index profile n(d) which is a function of depth d in the coating uses a first source material having a refractive index n.sub.H and a known rate of deposition r.sub.H and a second source material having a refractive index n.sub.L and a variable rate of deposition r.sub.L. The method includes the steps of setting the initial depth d to 0, then calculating the deposition rate r.sub.L (d) for the depth d according to the equation. ##EQU2## The first source material is then deposited at the rate r.sub.H and the second source material at the rate r.sub.L (d) for a time interval .DELTA.t. At the end of the time interval, the depth d is updated by adding an amount .DELTA.d=(r.sub.H +r.sub.L (d)) .DELTA.t. The steps of calculating, depositing, and updating are repeated until the predetermined refractive index profile is achieved.

REFERENCES:
patent: 3271179 (1966-09-01), Smith
patent: 4583822 (1986-04-01), Southwell
patent: 4666250 (1987-05-01), Southwell
MacLeod, H. A.; "Thin-Film Optical Filters"; 1986, pp. 131-136.
Knittl, Zdenek; "Optics of Thin Films"; 1976, pp. 471-479.
Jacobson, R.; "Inhomogeneous and Coevaporated Homogeneous Films for Optical Applications"; Physics of Thin Films; vol. 8, 1975; pp. 51-97.
Jacobson and Martensson; "Evaporated Inhomogeneous Thin Films"; Applied Optics, vol. 5, No. 1; Jan., 1966; pp. 29-34.
Gillett, Phillip; Calculus and Analytic Geometry; 1981; pp. 74-83.
Theeten, Ellipsometric Assessment of (Ga,Al) As/GaAs Epitaxial Layers During Their Growth in an Organometallic VPE System, Journal of Crystal Growth, vol. 46, p. 245 (1979).
Yadava, et al., Optical Behavior of Gradient-Index Multilayer Films, Thin Solid Films, vol. 21, p. 297 (1974).
Berning, Use of Equivalent Films in the Design of Infrared Multilayer Antireflection Coatings, J. of the Optical Soc. of America, vol. 52, p. 431 (1962).
Budde, Photoelectric Analysis of Polarized Light, Applied Optics, vol. 1, p. 201 (1962).
Dobrowolski, Completely Automatic Synthesis of Optical Thin Film Systems, Applied Optics, vol. 4, p. 937 (1965).
Epstein, The Design of Optical Filters, Journal of the Optical Society of America, vol. 42, p. 806 (1952).
Hauge, et al., Design and Operation of ETA, an Automated Ellipsometer, IBM Journal of Research & Development, p. 472 (Nov., 1973).
Hottier, et al., In Situ Monitoring by Ellipsometry of Meta-Organic Epitaxy of GaAlAs-GaAs Superlattice, J. of Applied Physics, vol. 51, p. 1599 (Mar., 1980).
Minot, Single-Layer, Graded Refractive Index Antireflection Films Effective from 0.35 to 2.5 u., J. of Optical Soc. of America, vol. 66, p. 515 (1976).
Netterfield et al., Characterization of Growing Thin Films by In Situ Ellipsometric, Spectral Reflectance and Transmittance Measurements, and Ion-Scattering Spectroscopy, Review of Scientific Instruments, vol. 56, p. 1995 (1985).
Snedaker, New Numerical Thin-Film Synthesis Technique, Journal of the Optical Society of America, vol. 72, p. 1732 (1982).
Southwell, Coating Design Using Very Thin High-and Low-Index Layers, Applied Optics, vol. 24, p. 457 (1985).
Southwell, Gradient-Index Antireflection Coatings, Optics Letters, vol. 8, p. 584 (Nov., 1983).

Affiliated with

Also associated with

Rating

Deposition of gradient index coatings using coevaporation with r does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Deposition of gradient index coatings using coevaporation with r, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Deposition of gradient index coatings using coevaporation with r will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2256308