United States Patent m
Holm-Kennedy et al.
 INTEGRATED OPTICAL WAVELENGTH
DISCRIMINATION DEVICES AND
METHODS FOR FABRICATING SAME
 Inventors: James W. Holm-Kennedy, 3215 Pacific
Heights Rd.. Honolulu. Hi. 95813;
Koon Wing Tsang. 2352 Walnut Grove
Ave.. San Jose. Calif. 95128; Datong
Yang. 744 East Georgia. Vancouver,
British Colombia. Canada, V6A 2A3
 Appl. No.: 312,286
 Filed: Apr. 26, 1994
Related U.S. Application Data
 Continuation-in-part of Ser. No. 681,695, Apr. 5, 1991, abandoned.
 Int. CI.6 G02B 6/293
 U.S. CI 385/31; 250/227.23; 356/416;
 Field of Search 385/14, 15 , 24.
385/27, 31, 36; 359/885, 887. 890; 356/352. 416. 419; 250/227.18. 227.23. 227.24. 226
 References Cited
U.S. PATENT DOCUMENTS
4,902,136 2/1990 Miieller et al 356/419
5,022,730 6/1991 Cimini et al 385/27
5,128,798 7/1992 Bowen et al 356/352 X
5,144,498 9/1992 Vincent 359/885
[ii] Patent Number: 5,784,507  Date of Patent: Jul. 21, 1998
Primary Examiner—John D. Lee
Attorney, Agent, or Firm—Flehr Hohbach Test Albritton & Herbert LLP
A top incident spectrometer includes a first distributed wavelength wedge filter region of order n t that discriminates incoming radiation as a function of wedge location, at least one second wedge region order n2 (which region may be a graded dielectric film), and an underlying detector array. In another embodiment, a second dielectric wedge element includes a Fabrey-Perot etalon. a wedge dielectric film, or a graded index film matching the second dielectric wedge region to an underlying substrate. One or more slopes associated with wedge elements may also be varied to alter filter characteristics. Spatial characteristics may further be modified by including a dielectric material whose dielectric constant varies as a function of location. Wedge filter crosstalk is minimized by partitioning a wedge dielectric region in the lateral dimension. Another embodiment provides an edge incident spectrometer including an optical waveguide or thin film structure whose spatial optical impedance varies as a function of position. Outcoupling of optical radiation occurs as a function of wavelength along the spectrometer propagation direction. Outcoupling of optical radiation may also be made to overlying structures, or to regions within a common, preferably solid state, structure. Wedge structures may further be combined to intentionally create gaps in the spectral transmission for a filter structure. A shadow masking fabricates thin film elements having spatially varying features. A material is deposited onto a substrate using an edge to provide a shadow mask affecting the deposition stream.
57 Claims, 27 Drawing Sheets