• Title/Summary/Keyword: slab waveguide

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Optical-Loss Measurement of a Silicon-Slab Waveguide

  • Tresna, Wildan Panji;Putra, Alexander William Setiawan;Maruyama, Takeo
    • Current Optics and Photonics
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    • v.4 no.6
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    • pp.551-557
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    • 2020
  • A mirror-in-slab waveguide is fabricated on a slab waveguide by using the refractive-index contrast between two materials, with the reflection performance depending on the slab waveguide's design. In this research, a slab waveguide design consisting of silicon (Si) as the core and SiO2 as the substrate was designed and developed to determine the coupling, waveguide, and mirror losses. Based on experimental results, coupling loss is dominant and is affected by the design of the slab waveguide. Furthermore, the mirror loss is affected by the design of the mirror, such as the curvature radius and the size of the mirror. TE and TM polarizations of light are used in the measurements. The experimental results show that mirror losses due to reflection by mirrors are 0.011 dB/mirror and 0.007 dB/mirror for TE and TM polarizations respectively. A simulation was performed to confirm whether the size of mirror is sufficient to reflect the input light, and to check the quality of the surfaces of fabricated mirrors.

Design of A Dielectric-Slab Polarizer in The Circular Waveguide (유전체판을 이용한 원형 도파관 편파기의 설계)

  • 김영민;안병철
    • Proceedings of the Korea Electromagnetic Engineering Society Conference
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    • 2000.11a
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    • pp.87-90
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    • 2000
  • In this paper. we present a method for a systematic design of a dielectric slab polarizer in the circular waveguide. This structure is realized using a tapered dielectric slab inside a circular waveguide. Commercial software is used to obtain the equivalent dielectric constant of the circular waveguide partially filled with a dielectric slab. The length of the tapered region is determined so that the reflection from the dielectric slab is sufficiently low. A polarizer operating at 10 GHz band is designed, fabricated and tested.

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Fabrication of Low Loss Silica Slab Waveguide by Flame Hydrolysis Deposition (FHD 공정에 의한 저손실 실리카 슬랩 도파로 형성)

  • 심재기;김태홍;신장욱;박상호;김덕준;성희경
    • Journal of the Korean Ceramic Society
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    • v.37 no.6
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    • pp.524-529
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    • 2000
  • Silica slab wavegudie was fabricated on Si substrates by FHD for planar optical passive devices. The slab waveguide consists of lower clad and core layers, where core layer index is controlled by GeO2 addition. Doping of GeO2 in silica is difficult because of the low deposition density due to nonspherical particle generation in FHD process. Silica core particles deposited at various conditions such as flame temperature and substrate scanning were analyzed by SEM and TEM. As the flame temperature increased, the surface roughness of the core layer was decreased up to 3.6 nm after consolidation. Index difference and thickness of core of slab waveguide were 0.3%, 8$\mu\textrm{m}$ respectively. Measured optical loss at TE mode was <0.04 dB/cm at 1.3$\mu\textrm{m}$ and <0.06 dB/cm at 1.55$\mu\textrm{m}$.

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Waveguide-type Multidirectional Light Field Display

  • Rah, Hyungju;Lee, Seungmin;Ryu, Yeong Hwa;Park, Gayeon;Song, Seok Ho
    • Current Optics and Photonics
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    • v.6 no.4
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    • pp.375-380
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    • 2022
  • We demonstrate two types of light field displays based on waveguide grating coupler arrays: a line beam type and a point source type. Ultra violet imprinting of an array of diffractive nanograting cells on the top surface of a 50-㎛-thin slab waveguide can deliver a line beam or a point beam to a multidirectional light field out of the waveguide slab. By controlling the grating vectors of the nanograting cells, the waveguide modes are externally coupled to specific viewing angles to create a multidirectional light field display. Nanograting cells with periods of 300 nm-518 nm and slanted angles of -8.5°~+8.5° are fabricated by two-beam interference lithography on a 40 mm × 40 mm slab waveguide for seven different viewpoints. It is expected that it will be possible to realize a very thin and flexible panel that shows multidirectional light field images through the waveguide-type diffraction display.

A Study on the Rectangular Waveguide Phase-Shifter Partially Loaded with a Rectangular Dielectric Slab (구형 유전체판이 삽입된 구형도파관 이상기에 관한 연구)

  • 박병우;이상설
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.15 no.10
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    • pp.850-856
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    • 1990
  • Generally, the waveguide phase-shifter has been analyzed by the modal expansion method. We can not apply this method in the case which is difficult to choose a nenerating function. In this paper, we are analyzed the rectangular waveguide phase shifter using the perturbation method. When the depth of dielectric slab is smaller then one half of the waveguide height, the experimental results are well agreed with the calculated values by this method.

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A Proposal of Simplified Eigenvalue Equation for an Analysis of Dielectric Slab Waveguide

  • Choi Young-Kyu
    • Journal of Electrical Engineering and Technology
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    • v.1 no.3
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    • pp.381-386
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    • 2006
  • In dielectric waveguide analysis and synthesis, we often encounter an awkward task of solving the eigenvalue equation to find the value of propagation constant. Since the dispersion equation is an irrational equation, we cannot solve it directly. Taking advantage of approximated calculation, we attempt here to solve this irrational dispersion equation. A new type of eigenvalue equation, in which guide index is expressed as a function of frequency, has been developed. In practical optical waveguide designing and in calculating the propagation mode, this equation will be used more conveniently than the previous one. To expedite the design of the waveguide, we then solve the eigenvalue equation of a slab waveguide, which is sufficiently accurate for practical purpose.

Analysis and Measurement of Effective Refractive Indices with Ion-exchanged Slab Waveguide (이온교환 평판도파로의 실효굴절율 측정 및 해석)

  • 천석표;박정일;박태성;정홍배
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1995.05a
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    • pp.73-76
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    • 1995
  • In this study, the slab waveguide was fabricated using potassium-nitride(KNO$_3$) or silver-nitride (AgNO$_3$) molten sources by ion-exchange process. The effective refractive indices of waveguide were measured by Prism-Coupling method. and The characteristics of waveguide(mode dispersion, effective diffusion depth. surface refractive index, diffusion coefficient, and refractive index profile etc,) were investigated by WKB method, In the case of potassium ion-exchange, the computer calculation showed that the refractive index profile of waveguide followed Gaussian function, the surface refractive index increased with ion-exchange time and the effective diffusion depth increased a little as ion-exchange time increased, while the surface refractive index of silver ion-exchanged waveguide decreased with ion-exchange time because of the ion depletion on the surface of waveguide, and the effective diffusion depth seriously with ion-exchange tim. Double ion-exchanged waveguide was fabricated by performing silver ion-exchange after potassium ion-exchange. Double ion-exchanged waveguide had a tight mode binding force since the surface refractive index was larger than single step ion-exchanged waveguide.

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The Slab Waveguide $CO_2$ Laser with Unstable Resonator of Negative Branch (Negative branch의 불안정 공진기를 갖는 슬랩형 도파관 $CO_2$ 레이저)

  • 김규식;우삼용;이영우;최종운
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.52 no.12
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    • pp.586-591
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    • 2003
  • We have developed the radio frequency excited slab waveguide $CO_2$ laser, The dimension of active area is $2{\times}40{\times}400$ mm to get a laser gain. Two pieces of concave mirror are used to make the unstable resonator of negative branch. The radio frequency is 123 MHz and RF input power is from 100 to 900 W. The laser gas is set to a pressure of 10 ∼ 60 torr and the mixing ration is $CO_2$:$N_2$:He=1:1:3. The laser output power of 50.9 W was obtained with laser power to RF power efficiency of 6.5 %.

Facet Reflectivities as a Function of Waveguide width of Buried Channel Waveguides using the Field Profiles Obtained by the Variational Method (Variational 방법으로 구한 필드 분포를 이용한 도파로 폭에 따른 Buried Channel Waveguides의 단면 반사율)

  • Kim, Sang-Taek;Kim, Dong-Hoo;Kim, Boo-Gyoun
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.37 no.11
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    • pp.36-42
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    • 2000
  • We calculate the facet reflectivity as a function of the waveguide width of buried channel waveguides using the angular spectrum method and the field profiles obtained by the effective index method, the variational method and the modified variational method, respectively and discuss the results. As the waveguide width increases, the facet reflectivity of buried channel waveguides approaches to that of slab waveguides. As the waveguide width decreases, the facet reflectivity of quasi-TE mode decreases from that of slab waveguides, while that of quasi-TE mode increases from that of slab waveguides. The variation of the facet reflectivity of quasi-TE mode as a function of waveguide width is much larger than that of quasi-TM mode. When the aspect ratio is one, the difference between the facet reflectivity of quasi-TE mode and that of quasi-TM mode using the variational method and the modified variational method is negligible, while the difference between the facet reflectivity of quasi-TE mode and that of quasi-TM mode using the effective index method is large. In the case of quasi-TE mode, the facet reflectivity using the angular spectrum method and the field profiles obtained by the modified variational method could be more accurate than that obtained by the effective method. In the case of quasi-TM mode, the facet reflectivities obtained by the various methods are almost the same.

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A Permittivity Measurement of Dielectric Slabs Using a Parallel Plate Waveguide (평행판 도파관을 이용한 유전율 측정 방법)

  • Cho, Gyo-Yeong;Park, Wee-Sang
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.12 no.2
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    • pp.199-203
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    • 2012
  • This paper introduces a simple new procedure approach to determine the permittivity of dielectric slabs. The method uses a parallel plate waveguide which supports a TEM mode. The presence of the dielectric slab placed at the bottom of the waveguide makes the speed of the TEM wave slower. The relationship between the change of the speed and the permittivity of the dielectric slab allows the determination of the permittivity. The relationship is analyzed electromagnetically, and the results of measurements are in good agreement with the analysis.