Optical thin films consisting of nanoscale laminated layers

The control of the refractive index of laminated coatings consisting of alternating stacks of nanoscale Al2O3 and TiO2 sublayers grown by atomic layer deposition has been achieved. The refractive index of the coating linearly changed from 1.870 to 2.318 as the thickness of the single TiO2 sublayer was varied from 2.0 to 39 A while that of the single Al2O3 sublayer was kept constant at 5.5 A. The refractive index could be varied by adjusting only the number of growth cycles of each material. This approach will have potential applications to optical multilayer coatings consisting of well-controlled extremely thin layers.

[1]  P. Herrmann,et al.  Fabrication of planar dielectric waveguides with high optical damage threshold , 1983 .

[2]  D. Aspnes.  Optical properties of thin films , 1982 .

[3]  Koichi Toyoda,et al.  Titanium oxide/aluminum oxide multilayer reflectors for "water-window" wavelengths , 1997 .

[4]  H. Zhang,et al.  High permittivity thin film nanolaminates , 2000 .

[5]  J. Gittleman,et al.  Composite material films: optical properties and applications. , 1976, Applied optics.

[6]  W H Southwell,et al.  Codeposition of continuous composition rugate filters. , 1989, Applied optics.

[7]  J A Dobrowolski,et al.  Comparison of the Fourier transform and flip-flop thin-film synthesis methods. , 1986, Applied optics.

[8]  R. W. Bertram,et al.  Experimental studies of inhomogeneous coatings for optical applications , 1991 .

[9]  L. Ivan Epstein,et al.  The Design of Optical Filters , 1952 .

[10]  D S -Germain,et al.  Synthesis of gradient-index profiles corresponding to spectral reflectance derived by inverse Fourier transform. , 1987, Applied optics.

[11]  Mikko Ritala,et al.  Tailoring the dielectric properties of HfO2–Ta2O5 nanolaminates , 1996 .

[12]  Mikko Ritala,et al.  Atomic layer epitaxy—a valuable tool for nanotechnology? , 1999 .

[13]  W H Southwell,et al.  Coating design using very thin high- and low-index layers. , 1985, Applied optics.

[14]  Peter H. Berning,et al.  Use of Equivalent Films in the Design of Infrared Multilayer Antireflection Coatings , 1962 .

[15]  W H Southwell,et al.  Gradient-index antireflection coatings. , 1983, Optics letters.

[16]  K. Hong,et al.  The deposition behavior of SiO2–TiO2 thin film by metalorganic chemical vapor deposition method , 2000 .

[17]  W. Southwell,et al.  Broadband gradient-index antireflection coating for ZnSe. , 1984, Applied optics.

[18]  Takahisa Jitsuno,et al.  Large-Area Optical Coatings with Uniform Thickness Grown by Surface Chemical Reactions for High-Power Laser Applications , 2002 .

[19]  M. Ritala,et al.  Introducing atomic layer epitaxy for the deposition of optical thin films , 1996 .