• 한국광학회지
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• 제27권4호
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• pp.127-132
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• 2016

본 논문에서는 다채널 가변광감쇠기에서 발생하는 열간섭 효과를 차단하여 광효율을 높이기 위하여 펨토초 레이저를 이용하여 트렌치를 가공하였다. 채널간 열간섭으로 인한 광감쇠 제어효율 하락을 막기 위하여, 가변광감쇠기 채널 사이에 펨토초 레이저로 트렌치의 폭과 깊이를 다르게 하여 가공하였고, 적용된 각 칩을 모듈화하여 전류에 따른 광감쇠율 변화를 관찰하였다. 그 결과 광감쇠를 위해 가해진 열이 주변채널에 영향을 매우 작게 미치는 것을 확인하였고, 뿐만 아니라 작은 전류에 광감쇠율이 민감하게 변화하는 것을 확인할 수 있어 효율적인 소자로서 개발 가능함을 확인하였다.

• 한국레이저가공학회지
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• 제17권3호
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• pp.10-14
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• 2014

By the specific character of femtosecond laser controlled volume of magnitude of micrometer scale could be ablated without melting phase in SKD11 and SUS304. According to the laser machining parameters various sectional shapes could be engraved on the surface of metals. Typical engraved lines were $10{\mu}m$ wide and deep. Coarse-milled surface was made $10{\mu}m$ lower than the original elevation by a bunch of laser-engraved lines in suitable spacing. The repeated banks with a height of $10{\mu}m$ could be made with the combination of the intact area.

• 한국레이저가공학회지
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• 제14권2호
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• pp.13-16
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• 2011

We fabricated the Fresnel zone plate using femtosecond laser lithography-assisted micro-machining, which is a combined process of nonlinear lithography and wet etching. We investigated the focusing properties by launching a 632.8nm wavelength He-Ne laser beam into the zone plate. The spot size of the primary focal point was $27{\mu}m$ and the intensity of focal point was 0.565W/$cm^2$.

• 한국레이저가공학회지
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• 제18권1호
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• pp.7-11
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• 2015

In this paper, micro trench structure is fabricated by femtosecond laser for inserting optical reflecting wavelength filter in planar waveguide. The width and depth of the trench is controlled by femtosecond laser machining condition. Also, large scale of single channel with 500um and 1000um on silica plate is fabricated by femtosecond laser, and roughness of the channel surface is polished by $CO_2$ laser for the insertion of the filter. Then, the characteristic of the planar waveguide inserted the filter is verified.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.640-643
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• 2003

We present investigations of the surface micromachining for transparent glass substrate, e.g. soda lime glass using tightly focused 800nm Ti:sapphire femtosecond laser. In this study, experiment conditions such as laser intensity, scanning speed, focus position were controlled as variable parameters to decide optimal machining conditions. This study shows clearly that laser intensity and scanning speed are dominant factors for good surface morphology. Using the optimal conditions, grooves with 50${\mu}{\textrm}{m}$ line width were fabricated on glass substrate and their surface morphologies were investigated from SEM image.

• 한국정밀공학회지
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• 제27권6호
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• pp.7-16
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• 2010

Physical fundamentals of ultrashort femtosecond lasers are addressed along with emerging applications for precision manufacturing and metrology. Femtosecond lasers emit short pulses whose temporal width is in the range of less than a picosecond to a few femtoseconds, thereby enabling extremely high peak-power machining with less thermal damages. Besides, the broad spectral bandwidth of femtosecond lasers constructed in the form of frequency comb permits absolute distance measurements leading to ultraprecision positioning control and dimensional metrology.

• International Journal of Precision Engineering and Manufacturing
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• 제7권1호
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• pp.13-17
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• 2006

Self-Assembled Monolayers (SAMs) formed by alkanethiol adsorption to thin metal film are widely being investigated for applications as coating layer for anti-stiction or friction reduction and in fabrication of micro structure of molecules and bio molecules. Recently, there have been many researches on micro patterning using the advantages of very thin thickness and etching resistance of Self-Assembled Monolayers in selective etching of thin metal film. In this report, we present the several machining method to form the nanoscale structure by Mask-Less laser patterning using alknanethiolate Self-Assembled Monolayers such as thin metal film etching and heterogeneous SAM structure formation.

• Design & Manufacturing
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• 제14권3호
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• pp.44-49
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• 2020

One of display trends today is development of high pixel density. To get high PPI, a small size of pixel must be developed. RGB pixel is arranged by evaporation process which determines pixel size. Normally, a fine metal mask (FMM; Invar alloy) has been used for evaporation process and it has advantages such as good strength, and low thermal expansion coefficient at low temperature. A FMM has been manufactured by chemical etching which has limitation to controlling the pattern shape and size. One of alternative method for patterning FMM is laser micromachining. Femtosecond laser is normally considered to improve those disadvantages for laser micromachining process due to such short pulse duration. In this paper, a femtosecond laser drilling for thickness of 16 ㎛ FMM is examined. Additionally, we introduce experimental results for controlling taper angle of hole by vibration module adapted in laser system. We used Ti:Sapphire based femtosecond laser with attenuating optics, co-axial illumination, vision system, 3-axis linear stage and vibration module. By controlling vibration amplitude, entrance and exit diameters are controllable. Using vibrating objective lens, we can control taper angle when femtosecond laser hole drilling by moving focusing point. The larger amplitude of vibration we control, the smaller taper angle will be carried out.

• 한국레이저가공학회지
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• 제16권4호
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• pp.1-6
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• 2013

Femtosecond laser patterning of ITO on a touch screen panel with a shaped fs laser beam was investigated. A quasi flat-top beam was formed using a variable mask and a planoconvex lens. The spatial profile of the original Gaussian beam and the shaped beam were monitored by a CCD beam profiler. The laser patterned ITO film was examined using an optical microscope, Scanning Electron Microscope (SEM) with Energy Dispersive X-ray Spectroscopy (EDS), and Atomic Force Microscope (AFM). It turned out that the quality of the ITO pattern fabricated by a shaped beam is superior to that of the pattern without beam shaping in terms of debris generation, height of the craters, and homogeneity of the bottom. Optimum processing window was determined at the laser irradiance exhibiting 100% removal of Sn. The removal rate of In was measured to be 83%.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2011년도 춘계학술대회 논문집
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• pp.39-40
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• 2011