Two-range antireflection coating of optical elements for thermal viewers

Gainutdinov, I. S.; Gusev, A. G.; Mustaev, R. M.; Nesmelov, E. A.; Никитин, А. А.

doi:10.1364/jot.69.000273

Cited by 3 publications

(4 citation statements)

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“…Many papers have reported on the design and development of AR coatings based on optical materials such as Ge, Y 2 O 3 , ZnS and YF 3 , etc which are widely employed for such purposes [16][17][18]. In our work, we have used Ta 2 O 5 , TiO 2 and SiO 2 .…”

Section: Design Of Ar Coatingsmentioning

confidence: 99%

Reactively evaporated multilayer antireflection coatings for Ge optical window

Asghar¹,

Placido²,

Naseem³

2007

J. Phys. D: Appl. Phys.

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Two multilayer antireflection (AR) coating configurations are designed, prepared and characterized. These AR coatings are designed for a 1 mm thick Ge optical window in the 3.25–5.25 µm band. Ta2O5 and TiO2 are used as high index materials along with SiO2 as low index material. Configuration 1 comprises nine alternating layers of SiO2 and Ta2O5, whereas configuration 2 comprises seven alternating layers of SiO2 and TiO2. Post-deposition annealing is also carried out in the temperature range 150–450 °C for 10 h. The prepared multilayered structures are characterized optically and structurally using a spectrophotometer, an atomic force microscope, x-ray diffraction and a scanning electron microscope. Optical characterization shows that multilayered structures have high absorption for as-deposited samples. A considerable improvement in the transmission profiles for the two multilayered configurations is observed at 350 °C with peak and average transmission for both the configurations exceeding 90%. The as-prepared samples show predominantly amorphous-like structure with pronounced peaks for configuration 2 only. Delamination (for configuration 1) and cracking (for configuration 2) of the multilayered structures are witnessed at an annealing temperature of 450 °C.

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Section: Design Of Ar Coatingsmentioning

confidence: 99%

Reactively evaporated multilayer antireflection coatings for Ge optical window

Asghar¹,

Placido²,

Naseem³

2007

J. Phys. D: Appl. Phys.

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show abstract

“…Many papers have reported on the design and development of antireflection coatings based on optical materials like Ge, yittria, ZnS, YF3 etc which are widely employed for such purposes [17][18][19]. In our work, we have used Ta2O5, TiO2 and SiO2 to arrive at two optimized designs.…”

Section: Introductionmentioning

confidence: 99%

“…It should be noted that SiO2 film surface shows larger particle size (40-60 nm) as compared to TiO2 (10-20 nm) and Ta2O5 (17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35) films, when measured form SEM. The surface quality of all the films appears to be suitable for multilayer applications.…”

Section: Introductionmentioning

confidence: 99%

Multilayer antireflection coatings for Ge optical window

Asghar

Placido

Naseem

2006

2006 IEEE International Multitopic Conference

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Two multilayer antireflection coatings have been designed, prepared and characterized for a 1 mm thick Ge optical window in 3.25-5.25 t band for optical and electro-optical application. Ta2O5 and TiO2 have been used as high index materials along with SiO2 as low index material. The prepared multilayer structures have been characterized optically and structurally using spectrophotometery, atomic force microscopy (AFM), x-ray diffraction (XRD), and scanning electron microscopy (SEM). Post deposition annealing of both multilayer structures have been carried out in the temperature range of 150-450°C for 10 hours, to study the effects of annealing on structure and transmission characteristics of the two configurations. Optical analysis shows that multilayer structure exhibits high absorption for the as-deposited samples which improves with subsequent annealing for both configurations. Structural realignment has been observed as soon as post deposition annealing is started and the film structure fails at annealing temperature of 450°C for both configurations, before the realignment process could complete. Configuration 1 has shown predominantly amorphous like structure, where as configuration 2 exhibited pronounced peaks with crystalline structure. A considerable improvement in the transmission profiles for the two multilayer configurations has been observed with highest transmission observed at 350°C with peak and average transmission for the both configurations has been found exceeding 90%. However, at 450°C, delamination and cracking of the two multilayer structures have been witnessed and its reasons have been studied.

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“…The approach used to design such a filter is different from the standard methods described by the above-mentioned expression. Antireflection coating design approach has been used to design the modular structure for band pass application [8][9][10][11][12]. The multilayer configuration has been optimized by varying the thickness and refractive indices of the layers.…”

Section: Introductionmentioning

confidence: 99%

Designing bandpass filters in 8 – 14 ?m range for Si and Ge substrates

Asghar¹,

Naseem²

2004

Semicond. Phys. Quantum Electron. Optoelectron.

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Modular bandpass spectral filter for germanium and silicon substrates in 8-14 μm band applications have been proposed. The design approach, similar to antireflection coating design has been adopted to make the model simple with lesser number of layers. The full width half maximum (FWHM) value of the filter for the two substrates is varied by varying the refractive index of a single layer in the multilayer stack. The design is also analyzed for zero and 45 degree angles of incidence. The analysis has shown that the designed configuration exhibits identical behavior for these two substrates. The proposed configuration could be used for different optical and optoelectronic applications.

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Two-range antireflection coating of optical elements for thermal viewers

Cited by 3 publications

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Reactively evaporated multilayer antireflection coatings for Ge optical window

Reactively evaporated multilayer antireflection coatings for Ge optical window

Multilayer antireflection coatings for Ge optical window

Designing bandpass filters in 8 – 14 ?m range for Si and Ge substrates

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