• Proceedings of the KIEE Conference
• /
• 1999.07g
• /
• pp.3298-3300
• /
• 1999

In this paper, a $10{\times}10$ micro SLM array for phase and amplitude modulation of incident light is designed and fabricated using surface micromachining technology. Hidden spring structure is used in order to maximize the fill-factor and minimize diffraction effect at the support posts. Static and dynamic characteristics of designed micro SLM are simulated with ABAQUS and measured with optical measurement system using He-Ne laser and PSD(position sensitive devise).

• Proceedings of the Optical Society of Korea Conference
• /
• 2003.07a
• /
• pp.270-271
• /
• 2003

링 레이저 자이로스코프는 회전각을 검출하는 센서로서 광학식이 가지는 정밀함과 견고성으로 관성항법을 비롯한 운동 제어를 필요로 하는 여러 분야에서 기존의 기계식 자이로스코프를 대체해 오고 있다. 링 레이저 자이로는 세 개 또는 네 개의 반사경으로 밀폐된 고리형 공진기를 구성하고 He-Ne 기체를 봉입하여 방전시킴으로써 서로 반대 방향으로 진행하는 레이저를 동시에 발진시키면 Sagnac 효과에 의해 공진기의 회전각에 비례하여 두 레이저의 주파수 차이가 발생하는 원리를 이용한다. (중략)

• Laser Solutions
• /
• v.14 no.3
• /
• pp.17-20
• /
• 2011

We fabricated a multi-layer diffraction grating inside fused silica glass by using a femtosecond laser direct writing method. The femtosecond laser with a wavelength of 515 nm, a pulse width of 250 fs, a repetition rate of 100 kHz, and an average output power of 6 W was used. Two layer diffraction grating with a grating period of $6{\mu}m$ was successfully fabricated with the layer gap of 0.5, 1, 2, 3, and $5{\mu}m$, respectively. Also, we investigated the diffraction pattern by illuminating a He-Ne laser beam. Finally, we demonstrated the diffraction grating with a grating period of $3{\mu}m$ by adjusting the gap of each layer with a grating period of $6{\mu}m$. Femtosecond laser direct writing technology of multi-layer has a potential to fabricate the diffraction grating with a grating period of below $1.5{\mu}m$.

• 제어로봇시스템학회:학술대회논문집
• /
• 1997.10a
• /
• pp.1415-1418
• /
• 1997

An accurate length measuring system has been develope by a modified Michelson interferometer. A frequency stabilized laser source and a 20 fold frequency interpolation and digitizing circuit were applied to the system. Resolutioin of .lambda./40, 16 nm, was achieved from the discrete length measuring system. In order to obtain a resoltuion of 1.mu.m a decimalizing module was designed for the 0.016.mu.m resolution system. The refractive index of the ambient air was calibrated on the decimalizing module through the Edlen's formula. Performance of the system was evaluated on the machining center in short and long length measruements.

• Proceedings of the Optical Society of Korea Conference
• /
• 1990.02a
• /
• pp.162-166
• /
• 1990

Photoinduced anisotropy (PIA) in amorphous As2S3 (a-As2S3 ) thin film, deposited by vacuum evaporation, is investigated. PIA is induced by linearly polarized Ar+ laser beam (λ=514.5nm) and probed by weak Ar+ laser (λ=514.5nm) and He-Ne laser (λ=632.8nm) beam through the crossed analyzer. Keeping pump beam intensity constantly, rotation of pump beam polarization direction induces reorientation phenomina of anisotropic axis. Introducing directional factor into simplified 3-level system, which is used to analyze photodarkening phenomina, an analytical expression of PIA is derived. Temporal behavior of PIAand its reorientation phenomina are investigated andcompared with theory. In the experiment pump beam intensity is 100mW/$\textrm{cm}^2$ and thickness of a-As2S3 thin film is 3${\mu}{\textrm}{m}$. In those condition, time constant of photoinduced anisotropy obtained by method of least square curve fitting is 4.0$\times$10-2sec-1. The time constant of PIA we obtained is larger than that of photodarkening, 2.8$\times$10-2sec-1.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1995.10a
• /
• pp.375-378
• /
• 1995

Although laser interferometer measurement system has the advantage of range and accuracy, the traditional error measurement methods for geometric errors(two straightness and three angular errors) of a machine tool measures error components one at a time. It may also create an optical path difference and affect the measurement accuracy. In order to identify and compensate for geometric error of a moving body, an on-line measurement system for simultaneous detection of the five error components of a moving axis is required. An on-line measurement system with 5 degrees of freedom was developed for geometric error detection. Performance verification of the system was performed on an error generating mechanism. Experimental results show the feasibility of this system for identifying geometric errors of a side of machine tool.

• Proceedings of the KOSOMBE Conference
• /
• v.1994 no.12
• /
• pp.101-103
• /
• 1994

The film scanner that digitizes the conventional x-ray films is the necessary equipment in the transition period of going to the filmless hospital. We have developed the film scanner using laser. We have selected HeNe laser as light source. The polygonal mirror converts the point light source to line scanning light. In sensing part, the diffusing cylinder and 7 photo transistors converts the light signal which passing the film into the electric signal. With this scanner, we can scan successfully the conventional x-ray film by $1024\times1024$. Smaller the spot sire is, higher the resolution can be achieved.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2006.11a
• /
• pp.110-111
• /
• 2006

In this paper, we investigated resistance characteristic of chalcogenide material for next generation ReRAM nonvolatile memory device with laser irradiation. A AES is used to test Ag doping ratio into a As-Ge-Se-S thin film. A sample resistance was observed in real time with He-Ne laser(632.8nm). As a result, resistance of thermal treated As-Ge-Se-S thin film was $500{\Omega}$ which is smaller than initial $1.3M{\Omega}$. A resistance of non-treated Ag/As-Ge-Se-S thin film was $200{\Omega}$ which is lower than $35M{\Omega}$.

• The Journal of Korean Medicine
• /
• v.17 no.2 s.32
• /
• pp.237-244
• /
• 1996

The purpose of this study was to investigate the effect of ILIB(Intravascular Laser Irradiation of blood) on Hyperfibrinogenemia. 20 patients with fibrinogen level of over $400mg／d{\ell}$ were treated with IUB. After !0 times' treatment, changes of fibrinogen level and clinical symptom were observed. The results were as follows: 1. Fibrinogen level was decreased in all of cases. 2. Most cases were suffered from neural symptoms(headache, palpitation, etc), circulatory symptoms (dizziness, numbness, deficiency of sensation, etc), musculo-skeletal symptoms(L.B.P, neck stiffness, arthralgia, etc.), fatigue, pollakiuria, constipation. After treatment, neural and circulatory symptoms were improved considerably.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 1995.03a
• /
• pp.17-23
• /
• 1995

This paper describes investigation of the dressing time by laser in the surface grinding operation. Always dressing work is done before grinding operation. And then generates wear and roading on the wheel by contact between the grinding performance but also ground surfaces. On these states dressing work is needed. On this paper contour of the wheel by He-Ne laser is measured. It has also been found that the wheel deflection reduces the actual depth of cut and the roughness of the ground surface.