• Journal of information and communication convergence engineering
• /
• 제1권4호
• /
• pp.228-232
• /
• 2003

The previous design work for very large final amplifier pumped by electron beam module was described from the point of view of energy characteristics. In this work, the design problems for phase front distortion, ASE, and gain control in large aperture amplifier are presented in detail.

• 한국자동차공학회논문집
• /
• 제22권6호
• /
• pp.14-22
• /
• 2014

An autonomous vehicle requires a technology of generating maps by recognizing surrounding environment. The recognition of the vehicle's environment can be achieved by using distance information from a 2D laser scanner and color information from a camera. Such sensor information is used to generate 2D or 3D maps. A 2D map is used mostly for generating routs, because it contains information only about a section. In contrast, a 3D map involves height values also, and therefore can be used not only for generating routs but also for finding out vehicle accessible space. Nevertheless, an autonomous vehicle using 3D maps has difficulty in recognizing environment in real time. Accordingly, this paper proposes the technology for generating 2D maps that guarantee real-time recognition. The proposed technology uses only the color information obtained by removing height values from 3D maps generated based on the fusion of 2D laser scanner and camera data.

• 한국전자통신학회논문지
• /
• 제16권4호
• /
• pp.725-734
• /
• 2021

타이어 사고를 방지하기 위해 앱 인벤터와 블루투스 통신을 이용한 타이어 안전을 확인할 수 있는 애플리케이션을 개발하였다. 온도 센서로 외부 온도를 측정하여 계절의 변화를 알고 압력센서로 타이어의 공기압을 측정하여 외부 온도에 맞는 공기압을 알려주며 레이저 센서의 거리를 50mm이상과 각도를 45°로 해야 최적화된 타이어의 마모도를 측정할 수 있었다. 마모도 측정된 수치에 따라 타이어의 상태를 판단하여 앱 인벤터를 사용하여 블루투스 모듈을 통해 연동한 후 사용자의 핸드폰으로 타이어의 상태와 예상교체를 알 수 안전을 확인할 수 있는 애플리케이션을 개발하였다.

• 한국전자통신학회논문지
• /
• 제2권4호
• /
• pp.228-235
• /
• 2007

레이저 거리 계측기는 과거에 주로 군사용으로 사용되어 헬기나 전차에 탑재하여 목표물과 발사체와의 거리를 측정하는데 사용하였다. 따라서 군사용의 경우 측정 거리가 수 km에서 수십 km 까지의 범위이며 측정하고자하는 오차도 5m 내외였다. 이와 같이 군사용 사용하던 레이저 거리 계측기를 산업용에 사용하고자 하는 노력이 계속되고 있으며 이에 본 논문에서는 산업용에 적용할 수 있는 산업용 레이저 거리 계측기를 개발하고 그 유용성을 검증하였다.

• 한국인터넷방송통신학회논문지
• /
• 제14권2호
• /
• pp.147-152
• /
• 2014

2단으로 구성된 DFB 레이저의 정적 및 동적 작용을 분석하기 위하여 종방향 모드 전송선로 이론 (L-MTLT)을 이용하였다. 활성영역을 갖는 DFB 구조의 특성 임피던스와 등가 전파상수를 L-MTLT에 기초하여 유도하였다. 2단으로 구성된 DFB 레이저가 전송선로 망으로 유사화 되었으며, 각 단은 그에 대응하는 등가 요소들로 등가화된 전송선로 블록으로 나타내었다. 등가 전송선로 망에 기초한 DFB 레이저의 종방향 공진 조건 (resonance condition)이 레이트 방정식 (rate equation)을 재구성하기 위하여 사용되었으며, 이를 이용하여 활성여역을 갖는 2단 DFB 레이저의 정적 및 동적 작용을 자세하게 분석하였다.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2001년도 제14회 신호처리 합동 학술대회 논문집
• /
• pp.777-783
• /
• 2001

This paper is mainly concerned with the state of the practical developments of a constants PWM bridge type resonants DC-DC suitable converter for Nd:YAG Laser with a Microprocessor. (PIC16C54 & 8051) The use of IGBT power supply with feedback control of flashLamp currents imparts a advantages to Nd:YAG Laser for materials processing. these include the alility to tailor the pulseshape and modify pulse parameters on a pulse- by pulse basis. And Correct choice of pulseshape can enhance the repeatability of the process. as higher power IGBT became available, act ive pulseforming power supplies will find greater user in deep hole drilling machine By Using certain control tecniques, utililized in designing Pic16c54 from Microchip technology and Intel 8051, also Mornitoring from Microsoft Visual Basic 5, And it allowed us to designed and fabricate ahigh repel it ion rate and high power(HRHP) pulsed Nd:YAG laser system, As a result of that, the current pulsewidth could be contort led 200s to 350s(step 50s) , and the pulse repetition rate could be adjusted 500pps to 1150pps. In addition, in the case of one laser head consisting of a Nd:YAG laser rod and two flashlamps , the maximum laser output of 240w was produced at the condition of 350s and 1150pps, and that of about 480w was generated at the same condition when two laser heads were arranged in cascade.

• 한국수소및신에너지학회논문집
• /
• 제28권6호
• /
• pp.729-737
• /
• 2017

The measurement accuracy of Tunable Diode Laser Absorption Spectroscopy based Tomography (TDLAST) for the temperature and concentration fields are dependant upon the arrangement method of the used laser beams. This paper reports on the optimization of laser beam arrangements using phantom data. It has been verified that the measurement error of the TDLAST decreased with increase of laser beam numbers. Further, it has been confirmed that perpendicular arrangements between the horizontal and the vertical laser beams without additional diagonal laser beams shows the minimum measurement errors.

• 대한용접접합학회:학술대회논문집
• /
• 대한용접접합학회 2000년도 특별강연 및 추계학술발표대회 개요집
• /
• pp.166-169
• /
• 2000

This paper presents a study on the LD Pump laser welded heat transfer and distortion analysis by using finite element method. In the production processing, ferrule and saddle of LD Pump in light-wave communication system are welded by multi mode Nd-YAG laser. Thus distortion happens during laser-welded packaging, and it makes an error of detecting the light signal translated through optical fiber in LD Pump. These parts experience thermal and mechanical hysteresis during heating and cooling process come from laser welding. The amount of final displacement is predicted using the finite element method. And the optimal shape is decided by using the result of pre-analysis.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2006년도 심포지엄 논문집 정보 및 제어부문
• /
• pp.342-344
• /
• 2006

During last years, large investments have been directed to development and research of nano-technological products like semiconductor, display panel, optic-fiber communication components, life technology, and ultra-precision components. All quantitative measurements at nanometre scale should guarantees accurate results and high quality. Laser interferometer is one of most famous nanometre scale devices to be able to measure metre-scale distance with nanometre scale resolution, but it is easily affected by various error causes like geometrical, instrumental and environmental factor. On the other side, capacitive sensor is robust to above error factors, but it is able to measure relatively shorter distance, under $100{\mu}m$, than laser interferometer. New error correction method for laser interferometry using capacitive sensor will be introduced in this paper.

• Current Optics and Photonics
• /
• 제4권6호
• /
• pp.461-465
• /
• 2020

A dual-mode laser terahertz source consisting of two in-line distributed Bragg reflector (DBR) laser diodes (LD) is proposed. It is less susceptible to residual reflections from facets than an in-line dual-mode distributed feedback (DFB) LD. The characteristics of the proposed terahertz source are theoretically investigated using a split-step time-domain simulation. It is shown that terahertz waves of frequencies from 385 GHz to 1725 GHz can be generated by appropriate thermal tuning of two DBR LDs. The dual-mode DBR LD terahertz source exhibits good spectral quality for residual facet reflectivity below 0.02, but facet reflectivity of the in-line dual-mode DFB LD terahertz source should be below 0.002 to provide similar spectral quality.