Multilayer antireflective and protective coatings comprising amorphous diamond and amorphous hydrogenated germanium carbide for ZnS optical elements

Abstract To effectively protect and improve the transmittance of ZnS optical elements in the far infrared band, combined amorphous diamond (a-D) and amorphous hydrogenated germanium carbide (a-Ge1−xCx:H) films have been developed. The optical interference coatings were designed according to the layer optics theory. The a-D films, of which refractive index and film thickness were controlled by changing substrate bias and deposition time respectively, were deposited by filtered cathodic vacuum arc technology. The a-Ge1−xCx:H films were prepared by radio frequency sputtering technology. During this process their refractive index was modulated by changing the gas flow rate ratio and their film thickness was controlled by the flow rate ratio and deposition time. It has been shown that the combined films are superexcellent antireflective and protective coatings for ZnS optical elements.

[1]  J. Robertson.  Structural models of a-C and a-C:H , 1995 .

[2]  R. Y. Lo,et al.  Annealing of nonhydrogenated amorphous carbon films prepared by filtered cathodic arc deposition , 2000 .

[3]  R. Kalish,et al.  Optical and photoemission studies of DLC films prepared with a systematic variation of the sp3:sp2 composition , 1997 .

[4]  S. Lau,et al.  THE DOUBLE BEND FILTERED CATHODIC ARC TECHNOLOGY AND ITS APPLICATIONS , 2000 .

[5]  L. Cescato,et al.  Measurement of optical constants of thin a-C:H films , 2000 .

[6]  P. Gaskell,et al.  Atomic structure of tetrahedral amorphous carbon , 1993 .

[7]  Peter M. Martin,et al.  Properties of reactively deposited SiC and GeC alloys , 1990, Optics & Photonics.

[8]  G. Amaratunga,et al.  Optical and electronic properties of amorphous diamond , 1993 .

[9]  Mckenzie,et al.  Neutron-scattering studies of the structure of highly tetrahedral amorphous diamondlike carbon. , 1991, Physical review letters.

[10]  F. Davanloo,et al.  Adhesion and mechanical properties of amorphic diamond films prepared by a laser plasma discharge source , 1992 .

[11]  D. Mckenzie,et al.  A theory for the formation of tetrahedral amorphous carbon including deposition rate effects , 1996 .

[12]  Ronald W. Waynant,et al.  Electro-Optics Handbook , 1994 .

[13]  R. Lappalainen,et al.  Modeling the ion energy dependence of the sp3/sp2 bonding ratio in amorphous diamondlike films produced with a mass‐separated ion beam , 1995 .

[14]  B. Tay,et al.  Optical properties of tetrahedral amorphous carbon films determined by spectroscopic ellipsometry , 1997 .

[15]  J. Wagner,et al.  Hard amorphous carbon studied by ellipsometry and photoluminescence , 1986 .

[16]  F. C. Marques,et al.  Optoelectronic and structural properties of a-Ge1−xCx:H prepared by rf reactive cosputtering , 1998 .

[17]  W. Y. Cheung,et al.  Optical properties of nitrogenated tetrahedral amorphous carbon films , 2002 .

[18]  Jiecai Han,et al.  Superexcellent infrared protective coatings : Amorphous diamond films deposited by filtered cathodic vacuum arc technology , 2007 .

[19]  M. Umeno,et al.  Structural and optical properties of diamond and nano-diamond films grown by microwave plasma chemical vapor deposition , 2001 .

[20]  C. Ronning,et al.  Cylindrical spike model for the formation of diamondlike thin films by ion deposition , 1998 .

[21]  Lee,et al.  Electronic structure of dense amorphous carbon. , 1994, Physical review. B, Condensed matter.

[22]  Daniel C. Harris,et al.  Infrared window and dome materials , 1992 .

[23]  McKenzie,et al.  Compressive-stress-induced formation of thin-film tetrahedral amorphous carbon. , 1991, Physical review letters.

[24]  A. Zeinert,et al.  Optical properties of amorphous hydrogenated carbon thin films , 2001 .

[25]  A. Bubenzer,et al.  Hard carbon coatings with low optical absorption , 1983 .

[26]  Q. Wei,et al.  Superhard diamondlike carbon: preparation, theory, and properties , 2000 .

[27]  Spectroscopic ellipsometric study of tetrahedral amorphous carbon films: optical properties and modelling , 2001 .

[28]  Jiecai Han,et al.  Chemical bonding of a-Ge1−xCx:H films grown by RF reactive sputtering , 2004 .

[29]  J. V. Bardeleben,et al.  Studies by electron paramagnetic resonance experiments of defects in hydrogenated amorphous carbon films as a function of annealing , 1996 .

[30]  P. Klocek.  Window and Dome Technologies and Materials III , 1989 .

[31]  Grossman,et al.  Substantiation of subplantation model for diamondlike film growth by atomic force microscopy. , 1994, Physical review letters.