• 전력전자학회:학술대회논문집
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• 전력전자학회 2014년도 전력전자학술대회 논문집
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• pp.59-60
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• 2014

In this paper, development of laser diode driver with 2.5kW rating is presented. The driver is configured with interleaved PFC converter, high frequency full bridge DC-DC converter, two laser diode drivers and ${\mu}$-processor based controller. The system has two laser diode drivers for providing high current and low current. High current driver delivers normal output power of diode; low current driver is for providing critical current of diode for long lifetime. Computer simulation and experiment was performed for verification, as the results, developed driver performs well.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 추계학술대회 논문집 학회본부 C
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• pp.1078-1080
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• 1999

A laser pulse generator which consists of charging resistor, energy storage capacitor laser diode, and switching elements was designed in order to generate 15ns, 20W laser pulses. And the effects of performances of SCR and FET as switching elements are compared. When SCR is used, the SCR's low maximum voltage makes the circuit so complicated, and when FET is used, the FET needs the special sate driver which improves the FET's operation.

• 전기학회논문지
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• 제64권5호
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• pp.746-750
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• 2015

In this paper, we propose a simulator to evaluate the performance of the semi-active laser guidance or the quadrant photodetector and to simulate the laser power reflected from a target. The laser pulse repetition frequency was generated and synchronized with the laser pulse repetition(PRF) code. To evaluate the performances of the proposed methods, we implemented a prototype system and performed experiments. As a result, the generated high voltage was variable in the range of DC 3V to 340V and has the rate of change of 2000 V/s. PRF code can be generated within 50ms ∼ 100ms and the error is implemented within 0.3ns. The laser output is synchronized with the PRF code and has a dynamic range of 23.6dB.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 추계학술대회 논문집
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• pp.423-426
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• 2005

A new chip on glass(COG) technique by making use of a high power diode laser for LCD driver IC packaging of LCD has been developed. A laser joining technology of the connection of IC chip to glass panel has several advantages over conventional method such as hot plate joining: shorter process time, high reliability of joining, and better fur fine pitch joining. The reach time to cure temperature of ACF in laser joining is within 1 second. In this study, results show that the total process time of joining is reduced by halves than that of conventional method. The adhesion strength is mainly 100-250 N/cm. It is confirmed that the COG technology using high power diode laser joining can be applied to advanced LCDs with a fine pitch.

• 전자공학회논문지D
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• 제35D권1호
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• pp.49-58
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• 1998

In this paper, a new equivalent circuit model for quantum-well laser diode (LD) is proposed. The model includes carrier transport effects in the SCH region, and rprovides, in a stable and accurate manner, large-and small-signal responses of laser diode output power as function of injected currents. SPICE simulation was performed using the circuit model and results are presented for L-I characteristics, pulse and frequency responses under various conditions. It is expencted that the new equaivalent circuit model will find useful applications for designing and analyzing OEIC, LD driver circuits, and LD packaging.

• 한국정보전자통신기술학회논문지
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• 제7권4호
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• pp.147-150
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• 2014

본 논문은 고속 고출력 레이저 다이오드(Laser Diode: LD) 구동에 사용되는 펄스형 전원장치의 개발에 관하여 논 하였다. 고속 고출력 레이저는 주로 가공기기나 의료기기 등에 응용되고 있어 그 사용 범위가 넓어지는 추세이나 관련된 기술에 대한 연구는 활발히 이루어지지 않은 편이다. 본 연구에서는 고속 고출력 LD의 구동에 적합한 LLC컨버터에 관한 연구를 수행 하였으며 특히 LD의 수명을 고려하여 구동 전류의 주파수를 유지하며 인가되는 전류의 크기를 임계전류를 고려한 방식으로 설계하여 드라이버 설계를 수행하였으며 그 결과를 실험을 통하여 확인하였다.

• Current Optics and Photonics
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• 제6권4호
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• pp.407-412
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• 2022

We report on a diode-laser-pumped mode-locked Yb:KGW laser system, which delivers ultrashort pulses down to 89 fs at a repetition rate of 63 MHz, with an average power of up to 5.6 W. A fiber-coupled diode laser at 981 nm, operated with a compact driver, is used to optically pump the gain crystal via an off-axis parabolic mirror. A semiconductor saturable-absorber mirror is used to initiate the pulsed operation. Laser characteristics such as the pulse duration, spectrum bandwidth, and output power are investigated by varying the intracavity dispersions via changing the number of bounces between negative-dispersive mirrors within the cavity. Short pulses with a duration of 89 fs, a center wavelength of 1,027 nm, and 3.6 W of output power are produced at a group-velocity dispersion (GVD) of -3,300 fs². As the negative GVD increases, the pulse duration lengthens but the output power at the single-pulse condition can be enhanced, reaching 5.6 W at a GVD of -6,600 fs². Because of pulse broadening at high negative GVDs, the highest peak intensity is achievable at a moderate GVD with our system.

• 한국정보통신학회논문지
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• 제19권3호
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• pp.667-673
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• 2015

레이져 다이오드(이하 LD)는 현재 의료용, 산업용 가공, 센서, 광고용기기, 인쇄장비 등등 많은 분야에서 연구되고 실제 산업현장에서 적용되어 사용되고 있다. 하지만 정밀한 취급이 요구되는 LD의 민감한 특성상 그 효용성에 비해서 실제 사용은 전문분야에 국한되어진다. 본 논문에서는 LD가 가지는 정전기, 전류, 열, 물리적 충격 등에 대한 민감한 특성을 고려하여, 다양한 파장대의 LD를 안정적으로 드라이빙 할 수 있는 샘플 모듈을 직접 제작해보고, 더 나아가 하나의 LD가 아닌 다수(다채널)의 LD 제어를 인쇄용 CTP(Computer To Plate) 장비를 통해 연구해 본다. 특히 현 CTP장비의 다채널 제어가 64채널에 한정되어 있음을 착안해, 이의 두 배인 128채널의 LD 제어를 목표로 하고, 이때 발생하는 시작점의 LD와 끝점의 LD 사이의 망점 간의 딜레이 문제점에 대한 해결 방안을 제시하고, 또한 실제 CTP 장비에 장착한 후 인쇄 속도와 해상도를 비교하여 128채널 LD 제어의 효율을 비교해본 후, 마지막으로 256채널 LD 제어의 가능성을 검토해본다.

• 한국레이저가공학회:학술대회논문집
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• 한국레이저가공학회 2006년도 추계학술발표대회 논문집
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• pp.53-81
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• 2006

A COG(Chip on Glass) bonding process that is one of display packaging technology and bonds between driver IC chip and a glass panel using ACF(Anisotropic Conductive Film)has been investigated by using diode laser. This method is possible to raise cure temperature of ACF within one second and can reduce the total process time for COG bonding by a conventional method such as a hot plate. Also we can get good pressure mark on the surface of electrodes and higher bonding strength than that by convention method. Results show that laser COG bonding can give low pressure bonding and decrease a warpage of panel. We believe that it can be applied to fine pitch module.

• 디지털산업정보학회논문지
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• 제10권2호
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• pp.13-20
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• 2014

In this paper, we implemented the object scanning with nxtOSEK which is an open source platform. nxtOSEK consists of device driver of leJOS NXJ C/Assembly source code, TOPPERS/ATK(Automotive real time Kernel) and TOPPERS/JSP Real-Time Operating System source code that includes ARM7 specific porting part, and glue code make them work together. nxtOSEK can provide ANSI C by using GCC tool chain and C API and apply for real-time multi tasking features. We experimented the 3D scanning with ultra sonic and laser sensor which are made directly by laser module diode and experimented the measurement of scanning the object by knowing x, y, and z coordinates for every points that it scans. In this paper, the laser module is the dimension of $6{\times}10[mm]$ requiring 5volts/5[mW], and used the laser light of wavelength in the 650[nm] range. For detecting the object, we used the beacon detection algorithm and as the laser light swept the objects, the photodiode monitored the ambient light at interval of 10[ms] which is called a real time. We communicated the 3D scanning platform via bluetooth protocol with host platform and the results are displayed via DPlot graphic tool. And therefore we enhanced the functionality of the 3D scanner for identifying the image scanning with laser sensor modules compared to ultra sonic sensor.