• Title/Summary/Keyword: Semiconductor laser

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Fabrication and Properties of Organic Semiconductor CuPccp LB Thin Film (유기 반도체 CuPccp LB초박막의 제작 및 특성)

  • Jho, Mean Jea;Xouyang, Saiyang;Lee, Jin Su;Ahn, Da Hyun;Jung, Chi Sup
    • Journal of Sensor Science and Technology
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    • v.28 no.1
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    • pp.23-29
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    • 2019
  • A copper tetracumylphenoxy phthalocyanine (CuPccp) thin film was formed on an organic insulator film by Langmuir-Blodgett (LB) deposition for gas sensor fabrication. To increase the reproducibility of film transfer, stearyl alcohol was used as a transfer promoter. The structural properties of the CuPccp layers were optically monitored through attenuated total reflection and polarization-modulated ellipsometry techniques. The average thickness of a single layer of the CuPccp LB film was measured to be 2.5 nm. Despite the role of the transfer promoter, the stability of the layer transfer was not sufficient to ensure homogeneity of the LB film. This was probably due to the presence of aggregates in the molecular structure of the CuPccp LB film. Nevertheless, copper phthalocyanine polymorphism can be greatly suppressed by the LB arrangement, which appears to contribute to the improvement of electrical conductivity. The p-type semiconductor characteristics were confirmed by Hall measurements from the CuPccp LB films.

Development of Scribing Machine for Dicing of GaN Wafer (GaN 웨이퍼의 다이싱을 위한 스크라이빙 머신의 개발)

  • Cha, Young-Youp;Go, Gyong-Yong
    • Journal of Institute of Control, Robotics and Systems
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    • v.8 no.5
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    • pp.419-424
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    • 2002
  • After the patterning and probe process of wafer have been achieved, the dicing processing is necessary to separate chips from a wafer. The dicing process cuts a semiconductor wafer to lengthwise and crosswise directions to make many chips. The existing general dicing method is the mechanical cutting using a narrow circular rotating blade impregnated diamond particles or laser cutting. Inferior goods can be made by the mechanical or laser cutting unless several parameters such as blade, wafer, cutting water and cutting conditions are properly set. Moreover, we can not apply these general dicing method to that of GaN wafer, because the GaN wafer is harder than general semiconductor wafers such as GaAs, GaAsP, AIGaAs and so forth. In order to overcome these problems, this paper describes a new wafer dicing method using fixed diamond scriber and precision servo mechanism.

Fabrication of Butt-Coupled SGDBR Laser Integrated with Semiconductor Optical Amplifier Having a Lateral Tapered Waveguide

  • Oh, Su-Hwan;Ko, Hyun-Sung;Kim, Ki-Soo;Lee, Ji-Myon;Lee, Chul-Wook;Kwon, Oh-Kee;Park, Sahng-Gii;Park, Moon-Ho
    • ETRI Journal
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    • v.27 no.5
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    • pp.551-556
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    • 2005
  • We have demonstrated a high-power widely tunable sampled grating distributed Bragg reflector (SGDBR) laser integrated monolithically with a semiconductor optical amplifier (SOA) having a lateral tapered waveguide, which is the first to emit a fiber-coupled output power of more than 10 dBm using a planar buried heterostructure (PBH). The output facet reflectivity of the integrated SOA using a lateral tapered waveguide and two-layer AR coating of $TiO_2\;and\;SiO_2$ was lower than $3\;{\times}\;10^{-4}\;over$ a wide bandwidth of 85 nm. The spectra of 40 channels spaced by 50 GHz within the tuning range of 33 nm were obtained by a precise control of SG and phase control currents. A side-mode suppression ratio of more than 35 dB was obtained in the whole tuning range. Fiber-coupled output power of more than 11 dBm and an output power variation of less than 1 dB were obtained for the whole tuning range.

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Inspection of combination quality for automobile steel balance weight using laser line projector and USB camera (레이저 선 프로젝터와 USB 카메라를 이용한 자동차용 철 밸런스 웨이트의 결합상태 검사)

  • Choi, Kyung Jin;Park, Se Je;Lim, Ho;Park, Chong Kug
    • Journal of the Semiconductor & Display Technology
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    • v.12 no.1
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    • pp.15-21
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    • 2013
  • In this paper, sensor system and inspection algorithm in order to inspect steel balance weight for automobile is described. Steel balance weight is composed of clip and weight, which is joined by press process. The defective one has a gap between clip and weight. To detect whether there is a gap, sensor system is simply configured with laser line projector and USB camera, which make it possible to measure the height difference of clip and weight area. Laser line pattern which is made on the surface of a balance weight is captured by USB camera. In case that USB camera is used in machine vision, barrel distortion caused by wide angle lens makes the captured image distorted. Image warping function is applied to correct the distortion. Simple image processing algorithm is applied to extract the laser line information and whether it is good or not is judged through the extracted information.

Measurement of angular velocity using the self-mixing effect of semiconductor laser (되먹임 효과를 이용한 회전체의 속도측정)

  • 이병욱
    • Korean Journal of Optics and Photonics
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    • v.11 no.4
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    • pp.250-254
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    • 2000
  • We have constructed laser Doppler velocimetry system using self-mixing effect with a semiconductor laser. This technology is based on the frequency mixing phenomena which occurs when light scattered back from the moving object into the laser cavity interferes with light inside the laser. We have compared the value of Doppler shifted frequency with the velocity variation of the wheel. Frequency dependence on the angle between the moving direction of rotating aluminum wheel and the incident beam also have been proved. As an illustration of the performance of the velocimeter, velocity measurements of a rotating disk are described. Doppler signal shows a good linear relationship with velocity of rotating disk.

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Properties of Y3Al5O12:Ce3+,Pr3+ Single Crystal for White Laser Lightings (백색 레이저 조명용 Y3Al5O12:Ce3+,Pr3+ 단결정 특성)

  • Kang, Taewook;Lim, Seokgyu;Kim, Jongsu;Lee, Bong
    • Journal of the Semiconductor & Display Technology
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    • v.17 no.4
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    • pp.37-41
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    • 2018
  • $Y_3A_{l5}O_{12}:Ce^{3+},Pr^{3+}$ single crystal phosphor was prepared by floating zone method. single crystal was confirmed to have a Ia-3d (230) space group of cubic structure and showed regular morphology. The optical properties, single crystal exhibited a emission band from green, yellow wide wavelength and 610nm, 640nm red wavelength vicinity. The luminance maintenance rate was decreased by phonon with increasing temperature, but high luminance is maintained more than powder phosphor. In addition, $Y_3A_{l5}O_{12}:Ce^{3+},Pr^{3+}$ single crystal phosphor was applied to a high power blue laser diode, we implemented high power white laser lightings. and it was confirmed that thermal properties over time, due to the effective heat transfer of complete crystal structure. We confirmed that excellent radiant heat properties than powder phosphor was applied to a high power white laser diode.

Process Study of Direct Laser Lithographic System for Fabricating Diffractive Optical Elements with Various Patterns (다중 패턴의 회절광학소자 제작을 위한 레이저 직접 노광시스템의 공정 연구)

  • Kim, Young-Gwang;Rhee, Hyug-Gyo;Ghim, Young-Sik;Lee, Yun-Woo
    • Journal of the Semiconductor & Display Technology
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    • v.18 no.2
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    • pp.58-62
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    • 2019
  • Diffractive Optical Elements(DOEs) diffracts incident light using the diffraction phenomenon of light to generate a desired diffraction image. In recent years, the use of diffraction optics, which can replace existing refractive optical elements with flat plates, has been increased by implementing various optical functions that could not be implemented in refractive optical devices and by becoming miniaturized and compacted optical elements. Direct laser lithography is typically used to effectively fabrication such a diffractive optical element in a large area with a low process cost. In this study, the process conditions for fabricating patterns of diffractive optical elements in various shapes were found using direct laser lithographic system, and optical performance evaluation was performed through fabrication.

The Conditions of a Holographic Homogenizer to Optimize the Intensity Uniformity (주기적인 홀로그램을 이용한 레이저 광 세기 균일화기에서 균일도를 최적화하기 위한 홀로그램의 조건)

  • Go, Chun-Soo;Oh, Yong-Ho;Lim, Sung-Woo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.24 no.7
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    • pp.578-583
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    • 2011
  • We report on the design of a holographic homogenizer composed of a periodic hologram and a condensing lens. If the hologram is periodic, the homogenizer is free from the alignment error of the incident laser beam. Holographic homogenizer also has an advantage of the flexibility in the size of the target beam. We calculated theoretically the Fraunhofer diffracted wave function when a rectangular laser beam is incident on a periodic hologram. The diffracted wave is the sum of sinc functions at regular distance. The width of each sinc function depends on the size of the incident laser beam and the distance between the sinc functions depends on the period of the hologram. We calculated numerically the diffracted light intensity for various ratios of the size of the incident laser beam to the period of the hologram. The results show that it is possible to make the diffracted beam uniform at a certain value of the ratio. The uniformity is high at the central part of the target area and low near the edge. The more sinc functions are included in the target area, the larger portion of the area becomes uniform and the higher is the uniformity at the central part. Therefore, we can make efficient homogenizer if we design a hologram so that the maximum number of the diffracted beams may be included in the target area.

Development of Auto Positioning Laser System by using Image Measurement Data (영상 측정 데이터를 이용한 위치보정 레이저 가공시스템 개발)

  • Pyo, Chang-Ryul
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.12 no.3
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    • pp.36-40
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    • 2013
  • Recently, electronic equipments become smaller, more functional, and more complex than before. As these trends, MLC(multi-layer ceramic) circuit has been emerged to a promising technology in semiconductor inspection industry. Especially, multi-layer ceramic which is consisted of many fine-pitch multi-hole is used to produce a semiconductor inspection unit. The hole is processed by UV laser. But, working conditions are changed all the time. Therefore real time measurement of fine-pitch multi-hole is very important method for ensuring performance. In this paper we found the best method for illuminating and auto focusing. And, we verified our equipment.

A Study on the Motion Characteristics of the Ultrasonic Transport System using Laser Scanning Vibrometer (레이저 진동 측정기를 이용한 초음파 이송 시스템의 동작특성에 관한 연구)

  • 정상화;신병수;이경형
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2003.10a
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    • pp.155-158
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    • 2003
  • In the semiconductor and the optical industry a new transport system which can replace the conventional sliding system is required. These systems are driven by magnetic field and conveyer belt. The magnetic field damages semiconductor and contact force scratches the optical lens. The ultrasonic wave driven system can solve these problem. In this paper, the vibration behavior of flexural beam in the ultrasonic transport system is verified using Laser Scanning Vibrometer. The experiments for verifying vibration are performed in three conditions such as in the maximum transport speed, in the zero speed, and in the change of transport direction.

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