Broadband antireflection coatings

Optical Properties. The addition of lanthanum oxide to PZT has a rather remarkable effect on the optical transparency, especially when the amount of lanthanum exceeds seven atom percent. Thin polished plates characteristically transmit about 67% of the incident light. When broadband antireflection coatings are applied to the major surfaces, this transmission is increased to greater than 98%. Surface reflection losses are a function of the index of refraction (n = 2.5) of the PLZT. 

Modem broadband antireflection coatings generally consist of three to seven layers. The following four layer a.r. coating design on crown glass was created by Shadbolt [58] ... 

Chi, F., Yan, L., Haibing, L.V., Yan, H., Yuan, X., and Jiang, B. (2012) Sol-gel preparation of ultralow refractive index magnesium fluoride optical films for broadband antireflective coatings. Nanosci. Nanotechnol. Lett., 4,441 444. 

Debsikdar J (1989) Broadband antireflective coating composition and method. Google Patents... 

To justify the basic propagation equation (5.14) or (5.19), it is essential that there be no reflections from interfaces. This means that either the individual layers be coated for broadband antireflection or that the incremental change of optical properties p. cp across an interface is small. 

Antireflection coatings for infrared materials such as Si, Ge, InAs and InSb have been designed extensively by Cox and various coworkers [59-61]. A commercially available multilayer broadband a.r. system for Ge is shown in Fig.6. For ultraviolet applications, only MgF2 single layers or double layers are used because of the lack of suitable high-index film materials which would satisfy the requirements for half wave films. 

Measured curves for germanium samples coated with the broadband antireflection films INFRALIN 211 (Balzers). 

X. Li, J. Gao, L. Xue, Y. Han, Porous polymer films with gradient-refractive-Index structure for broadband and omnidirectional antireflection coatings. Advanced Functional Materials 20 (2010) 259-265. 

Figure 4.59 Antireflection coatings, a Single layer Mgp2 on substrates with different refractive index b-d broadband multilayer AR-coatings, optimized for different spectral ranges...

Paz Y., Luo Z., Rabenberg L., Heller A. Photooxidative self-cleaning transparent titanium dioxide film on glass. J. Mater. Res. 1995 10 2842-2848 Prend P., Priotton J.J., Beaurain L., BeUevUle P. Preparation of a sol-gel broadband antireflective and scratch-resistant coating for amplifier blastshields of the French laser LIL. J. Sol-Gel Sci. Technol. 2000 19 533-537... 

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