• Title/Summary/Keyword: Waveguide

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Rectangular Waveguide-NRD Waveguide Transition having the NRD Waveguide Built-in Structure (NRD 도파관에 내장된 구조를 갖는 구형 도파관-NRD 도파관 트랜지션)

  • Yoo, Young-Geun;Choi, Jae-Ha
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.19 no.4
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    • pp.391-396
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    • 2008
  • In this paper, we proposed the new rectangular waveguide-NRD waveguide transition in which the transition function about the standard waveguide is built in within the NRD waveguide ifself. The newly proposed rectangular waveguide-NRD waveguide transition was realized use of NRD waveguide input/output side wall thickness and hole width. In the case of the wall thickness, it was nearly identical with the half of the NRD waveguide guide wavelength and the width of an hole was nearly coincide with the length of the long side of the standard waveguide connected with the NRD waveguide. This kind of the principles is applicable to be unrelated with the frequency band. In this paper, it made in 38 GHz band with the rectangular waveguide-NRD waveguide transition and the feasibility was confirmed. In the back-to-back structure, the rectangular waveguide-NRD waveguide transition manufactured in 38 GHz band has the insertion loss less than 0.4 dB and also has the return loss less than 20 dB.

Soft Optical Waveguide Sensors Tuned by Reflective Pigmentation for Robotic Applications (로봇 어플리케이션을 위해 반사 색소로 조정된 소프트 광도파로 센서)

  • Jamil, Babar;Choi, Youngjin
    • The Journal of Korea Robotics Society
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    • v.16 no.1
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    • pp.1-11
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    • 2021
  • Soft robotics has attracted a huge amount of interest in the recent decade or so, be it either actuators or sensors. Recently, a soft optical waveguide sensor has proven its effectiveness for various sensing applications such as strain, force, and bending measurements. The operation principle of the waveguide is simple, but the present technology is far too much complex to manufacture the waveguide. The waveguide fails to attract various practical applications in comparison to other types of sensors despite its superior safety and ease working principle. This study pursues to develop the soft sensors based on the optical phenomena so that the waveguide can be easily manufactured and its design can be conducted. Several physical properties of the waveguide are confirmed through the repetitive experiments in the aspects of strain, force, and bending of the waveguide. Finally, the waveguide sensor is embedded inside the actuator to verify the effectiveness of the proposed waveguide as well as to extend the application fields of the waveguide sensor.

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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    • 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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Mode Propagation in X-Ray Waveguides

  • Choi, J.;Jung, J.;Kwon, T.
    • Journal of the Optical Society of Korea
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    • v.12 no.2
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    • pp.112-117
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    • 2008
  • Single-mode propagation conditions of X-ray waveguides are investigated by numerical calculations in order to understand the importance of waveguide design parameters, such as core thickness and the optical constants of waveguide materials, on the transmission and coherence properties of the waveguide. The simulation code for mode analyzing is developed based on a numerical solution of the parabolic wave equation. The initial boundary value problem is solved numerically using a finite-difference scheme based on the Crank-Nicolson scheme. The E-field intensities in a core layer are calculated at an X-ray energy of 8.0 keV for air and beryllium(Be) core waveguides with different cladding layers such as Pt, Au, W, Ni and Si to determine the dependence on waveguide materials. The highest E-field intensity radiated at the exit of the waveguide is obtained from the Pt cladded beryllium core with a thickness of 20 nm. However, the intensity from the air core waveguide with Pt cladding reaches 64% of the Be-Pt waveguide. The dependence on the core thickness, which is the major parameter used to generate a single mode in the waveguide, is investigated for the air-Pt, and Be-Pt waveguides at an X-ray energy of 8.0 keV. The mode profiles at the exit are shown for the single mode at a thickness of up to 20 nm for the air-Pt and the Be-Pt waveguides.

Beam Splitting by the Use of Waveguide Airy Beams

  • Kim, Kyoung-Youm;Kim, Sae-Hwa
    • Journal of the Optical Society of Korea
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    • v.15 no.4
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    • pp.403-406
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    • 2011
  • Here we report Airy beams coupled with waveguide modes. These waveguide Airy (WAiry) beams propagate through layered planar structures inheriting the characteristics of waveguide modes as well as those of Airy beams, such as diffraction-free and accelerating features. In particular, we focus on the WAiry beams associated with backward waveguide modes, showing that the backward feature can alter the trajectories of the WAiry beams significantly. Based on this, we propose a new scheme of waveguide-type polarization/power beam splitters.

Fabrication and Characteristics Analysis of Ti:LiNbO$_{3}$ Optical Waveguide (Ti:LiNbO$_{3}$ 광도파로 제작 및 특성분석)

  • 윤형도;김성구;이한영;윤대원
    • Journal of the Korean Institute of Telematics and Electronics D
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    • v.35D no.7
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    • pp.109-116
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    • 1998
  • In this work was produced and analyzed a z-cut Ti:LiNbO$_{3}$ optical waveguide which applies for various optical devices.A waveguide channel with a thickness 8 .mu.m and a length 66,000.mu.m and a mach-zehnder interferometer type waveguide were fabricated at a diffusion temperature 1050.deg. C for 6-8hours in a wet $O_{2}$ environment. The resulting Ti:LiNbO$_{3}$ optical waveguide was measured to have a Ti-strip thickness of 950.angs. and low loss. Surfaces and cross-sections of a fabricated waveguide were analysed. The mode pattern anaysis revealed that the waveguide showed a single mode at a 1550nm wavelength. The effective dimension of the waveguide was calculated by measuring a gaussian profile; Wx=10.95.mu. and Wy=9.14.mu.m. a propagation loss, of 0.50dB/cm for a TM mode and 0.45dB/cm for a TE mode, was low enough to be accepatable for optical devices.

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The guided field distribution characteristics in the ion-exchange channel glass waveguide (이온 교환 채널 유리 도파로의 도파광 분포특성)

  • 박정일;박태성;천석표;정홍배
    • Electrical & Electronic Materials
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    • v.8 no.3
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    • pp.332-339
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    • 1995
  • In this paper, it was investigated the guided field intensity distribution of the channel in the silver & potassium ion-exchange glass-waveguide. The guided field intensity distribution analysis of ion-exchange glass-waveguide was based on the combination of the WKB dispersion relationship method with a Gaussian distribution function of refractive index profile and the Field Shadow method to the modeling of the channel waveguide. As the results of the channel waveguide modeling, it was represented 2-dimensional and 3-dimensional field distribution of ion-exchange glass waveguide.

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Fabrication of Planar Type Optical Waveguide for the Application of Biosensor and Detection Characteristics of Staphylococcus Aureus (바이오센서용 평판형 광도파로 센서 제작 및 황색포도상구균 검출 특성)

  • Kim, Jun-Hyong;Yang, Hoe-Young;Yu, Chong-Hee;Lee, Hyun-Yong
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.223-223
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    • 2009
  • In this paper, designed and simulated Power Splitter (PS) integrated Mach-Zehnder interferometer (MZI) based planar type optical waveguide devices (which is called here a PS-MZI). The PS-MZI optical waveguide sensor was preceded by a Y-junction, which splits the input power between the sensor, and a reference branch, to minimize the effect of optical power variations. The PS-MZI optical waveguide sensor induced changing phases of the incident beam, which had fallen upon the waveguide through computer simulation, according to the small changes in the index of refraction, thus beam intensity was changed. The waveguide were optimized at a wavelength of 1550 nm and fabricated according to the design rule of 0.45 delta%, which is the difference of refractive index between the core and clad. The fabrication of PS-MZI optical waveguide sensor was performed by a conventional planar lightwave circuit (PLC) fabrication process. The PS-MZI optical waveguide that was fabricated to be applied as a biosensor revealed a low insertion loss and a low polarization-dependent loss. After having etched the over-clad at the sensor part in the MZI optical waveguide that was fabricated, Ti deposition was made on the adhesion layer, and then Au thin-film deposition was carried out thereon. In addition, its optical properties were measured by having changed the index of refraction oil at the sensing part of the MZI. To apply the planar type PS-MZI optical waveguide as a biosensor, a detection test for Staphylococcus aureus was conducted according to changes in concentration, having adopted Ti-alkoxide as ligand. The detection result of the S. aureus by the PS-MZI optical waveguide sensor was possible to the level of $10^1$ CFU/ml.

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Improving Wave Propagation Performance of an Ultrasonic Waveguide for Heat Isolation (열 차단용 초음파 도파관의 전파성능 향상 연구)

  • 최인석;전한용;김인수;김진오
    • The Journal of the Acoustical Society of Korea
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    • v.22 no.7
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    • pp.545-553
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    • 2003
  • This paper is concerned with protecting piezoelectric transducers used in an ultrasonic flowmeter from the high temperature of hot fluid in a pipe by using a waveguide and with improving the propagation of ultrasonic longitudinal vibration in the waveguide. Waveguide material has been chosen for efficient insulation of heat transferred in the waveguide, and the minimum length of the waveguide for protecting piezoelectric transducer has been estimated. Forced response of the longitudinal vibration in a uniform circular rod has been obtained and the length of the waveguide has been selected for maximum amplitude. Longitudinal vibration response of a conically-tapered rod excited at a natural frequency has been obtained to confirm that wave motion is amplified as the cross-sectional size of the waveguide decreases along the axial direction. The fact that dispersion of a pulse wave in a waveguide is reduced as the cross-sectional radius is decreased has been examined theoretically and confirmed experimentally by using a single-rod waveguide. A bundle-type waveguide has proven to be a practical one through the evaluation of the wave propagation performance.

Narrow Resonant Double-Ridged Rectangular Waveguide Probe for Near-Field Scanning Microwave Microscopy

  • Kim, Byung-Mun;Son, Hyeok-Woo;Cho, Young-Ki
    • Journal of Electrical Engineering and Technology
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    • v.13 no.1
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    • pp.406-412
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    • 2018
  • In this paper, we propose a narrow resonant waveguide probe that can improve the measurement sensitivity in near-field scanning microwave microscopy. The probe consists of a metal waveguide incorporating the following two sections: a straight section at the tip of the probe whose cross-section is a double-ridged rectangle, and whose height is much smaller than the waveguide width; and a standard waveguide section. The advantage of the narrow waveguide is the same as that of the quarter-wave transformer section i.e., it achieves impedance-matching between the sample under test (SUT) and the standard waveguide. The design procedure used for the probe is presented in detail and the performance of the designed resonant probe is evaluated theoretically by using an equivalent circuit. The calculated results are compared with those obtained using the finite element method (Ansoft HFSS), and consistency between the results is demonstrated. Furthermore, the performance of the fabricated resonant probe is evaluated experimentally. At X-band frequencies, we have measured the one-dimensional scanning reflection coefficient of the SUT using the probe. The sensitivity of the proposed resonant probe is improved by more than two times as compared to a conventional waveguide cavity type probe.