Antireflection coatings for germanium IR optics: a comparison of numerical design methods

Aguilera, J.A.; Baumeister, Philip; Bloom, Arnold L.; Coursen, D.; Dobrowolski, J. A.; Goldstein, Fred T.; Gustafson, Darryl E.; Kemp, Roger

doi:10.1364/ao.27.002832

Cited by 64 publications

(25 citation statements)

References 18 publications

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“…Eq. (2) is a standard equation (in the subcritical angle regime) from impedance matching theory, 18,19 used for example in antireflection coatings at IR and THz frequencies, [19][20][21][22] …”

mentioning

confidence: 99%

Exploiting total internal reflection geometry for efficient optical modulation of terahertz light

Parrott

Ung

et al. 2016

APL Photonics

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Efficient methods to modulate terahertz (THz) light are essential for realizing rapid THz imaging and communication applications. Here we report a novel THz modulator which utilizes the evanescent wave in a total internal reflection setup coupled with a conductive interface to enhance the attenuation efficiency of THz light. This approach makes it possible to achieve close to 100% modulation with a small interface conductivity of 12 mS. The frequency dependence of this technique is linked to the optical properties of the materials: a material with close to frequency independent conductivity that is also controllable will result in an achromatic modulation response, and the device performance can be optimized further by tuning the internal reflection angle. In this work, we focus on applying the technique in the terahertz frequency range. Using an LED array with a pump intensity of 475 mW/cm2 to produce carriers in a silicon wafer, we have achieved a modulation depth of up to 99.9% in a broad frequency range of 0.1 THz–0.8 THz. The required pumping power for the generation of the required free carriers is low because the sheet conductivity needed is far less than required for traditional transmission techniques. Consequently, the device can be modulated by an LED making it a very practical, low cost, and scalable solution for THz modulation.

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confidence: 99%

Exploiting total internal reflection geometry for efficient optical modulation of terahertz light

Parrott

Ung

et al. 2016

APL Photonics

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“…The population size is 50. These parameters are decided after the experiments have been conducted on some optical coating problems (Aguilera et al, 1988;Li and Dobrowolski, 1992;Sullivan and Dobrowolski, 1996) with various values.…”

Section: Resultsmentioning

confidence: 99%

“…At least 60 different solutions were published for this AR coating, including non-evolutionary approaches (Aguilera et al, 1988;Dobrowolski and Kemp, 1990;Dobrowolski, 1997;Druessel and Grantham, 1993) and evolutionary approaches (Bäck and Schütz, 1995;Schutz and Sprave, 1996), which are mixed-integer algorithms. In contrast, our proposed approach is a real-valued optimizer.…”

Section: Infrared Antire Ection Coatingmentioning

confidence: 99%

“…The two basic approaches to the design of numerical optical coatings are re nement methods (Aguilera et al, 1988;Dobrowolski and Kemp, 1990) and synthesis methods (Dobrowolski, 1986;Li and Dobrowolski, 1992;Tikhonravov, 1993;Bovard, 1988). Re nement methods normally require a starting design, which is gradually modi ed to a desired solution.…”

Section: Introductionmentioning

confidence: 99%

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Optical Coating Designs Using the Family Competition Evolutionary Algorithm

Yang

Horng

Lin

et al. 2001

Evolutionary Computation

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A robust evolutionary approach, called the Family Competition Evolutionary Algorithm (FCEA), is described for the synthesis of optical thin-film designs. Based on family competition and adaptive rules, the proposed approach consists of global and local strategies by integrating decreasing mutations and self-adaptive mutations. The method is applied to three different optical coating designs with complex spectral quantities. Numerical results indicate that the proposed approach performs very robustly and is very competitive with other approaches.

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“…To compare various AR coatings we used the merit function defined as a root mean square (rms) reflectance of the system F = R2(X,) (1) where R is the normal energy reflectance, is the vector of design parameters of the system and Xi,. .…”

Section: Comprehensive Search Techniquementioning

confidence: 99%

Antireflection coating on GaAs for the range 8-12 μm

Hrdina¹,

Jastrabı́k²,

Potmesil³

et al. 1993

SPIE Proceedings

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The antireflection coating design on GaAs for the spectral range from 8im to 12,im is discussed. Based on the comprehensive search technique the best systems of up to 5 layers of ZnS and Ge are presented.To get better antireflection effect the materials with lower refractive indices are needed. Utilization of yttria for this purpose is suggested and optical constants in JR for both evaporated and sputtered layers are established.Though evaporated yttria layers exhibit relatively high absorption in the region of our interest, sputtered films are much better and several systems of up to four layers of Y203, ZnS and Ge are computed by the comprehensive search technique again.

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Antireflection coatings for germanium IR optics: a comparison of numerical design methods

Cited by 64 publications

References 18 publications

Exploiting total internal reflection geometry for efficient optical modulation of terahertz light

Exploiting total internal reflection geometry for efficient optical modulation of terahertz light

Optical Coating Designs Using the Family Competition Evolutionary Algorithm

Antireflection coating on GaAs for the range 8-12 μm

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