• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2001년도 ICCAS
• /
• pp.161.6-161
• /
• 2001

Confocal scanning microscopy (CSM) has an important role as the three-dimensional profiler. An image distribution can be reconstructed by a correlation analysis of spots with the bandwidth of radio frequency. But it is a serious problem for the high performance to align the optical components. Especially, the parasitic motion of focus on the detector gives rise to the fatal distortion of an image profile named the extinction effect while using acousto-optical(AO) deflector. An image profile can be regenerated in CSM with many advantages of non-contact, high speed and high resolution comparatively. In addition to the axial response of the primary focus, the lateral movement of it gives a necessity of the unitary lens to the scanning system. While using the beam deflector, the pupil of beam may be fixed at the nominal position. Furthermore, the use of a deflector may result in ...

• 대한기계학회논문집B
• /
• 제28권2호
• /
• pp.230-237
• /
• 2004

This paper suggests and demonstrates a novel flow measurement technique: tunable AC thermal anemometry that allows simple integration, robust measurement, and extremely high accuracy. The principle and simple theoretical analysis of the technique are presented. To find the optimal condition at which the phase lag becomes most sensitive to flow speed change, the phase lag was measured scanning the heating frequency from 1 to 100 Hz, while the flow speed of ethanol was increased stepwise from 0 to 40 mm/s. The sensitivity of phase lag depended on the heating frequency and the flow speed. It was possible to measure the flow speed of 0.7 mm/s with the resolution of 0.1 mm/s at 4 Hz.

• 한국가시화정보학회지
• /
• 제11권2호
• /
• pp.41-45
• /
• 2013

Two-photon microscopy (TPM) is minimally-invasive 3D fluorescence microscopy based on nonlinear excitation, and TPM can visualize cellular structures based on auto-fluorescence. Line-scanning TPM is one of high-speed TPM methods without sacrificing the image resolution by using spatial and temporal focusing. In this paper, we developed line-scanning TPM based on spatial and temporal focusing for auto-fluorescence imaging by exciting the tryptophan. Laser source for this system was an optical parametric oscillator (OPO) and it made near 570 nm femtosecond pulse laser. It had 200fs pulse width and 1.72 nm bandwidth, so that the achievable depth resolution was 2.41um and field of view (FOV) is 10.8um. From the characterization, our system has 3.0 um depth resolution and 12.3 um FOV. We visualized fixed leukocyte cell sample and compared with point scanning system.

• 한국정밀공학회지
• /
• 제25권1호
• /
• pp.122-129
• /
• 2008

Two-photon stereolithography is recognized as a promising process for the fabrication of three-dimensional (3D) microstructures with 100 nm resolution. Generally, beam-scanning system has been used in the conventional process of two-photon stereolithography, which is limited to the fabrication of micro-prototypes in small area of several tens micrometers. For the applications to 3D high-functional micro-devices, the fabrication area of the process is required to be enlarged. In this paper, large-area two-photon stereolithography (L-TPS) employing stage scanning system has been developed. Continuous scanning method is suggested to improve the fabrication speed and parameter study is conducted. An objective lens of high numerical aperture (N.A.) and high strength material were employed in this system. Through this work, 3D microstructures of $600*600*100\;{\mu}m$ were fabricated.

• Applied Microscopy
• /
• 제50권
• /
• pp.25.1-25.11
• /
• 2020

Scanning acoustic microscopy (SAM) or Acoustic Micro Imaging (AMI) is a powerful, non-destructive technique that can detect hidden defects in elastic and biological samples as well as non-transparent hard materials. By monitoring the internal features of a sample in three-dimensional integration, this technique can efficiently find physical defects such as cracks, voids, and delamination with high sensitivity. In recent years, advanced techniques such as ultrasound impedance microscopy, ultrasound speed microscopy, and scanning acoustic gigahertz microscopy have been developed for applications in industries and in the medical field to provide additional information on the internal stress, viscoelastic, and anisotropic, or nonlinear properties. X-ray, magnetic resonance, and infrared techniques are the other competitive and widely used methods. However, they have their own advantages and limitations owing to their inherent properties such as different light sources and sensors. This paper provides an overview of the principle of SAM and presents a few results to demonstrate the applications of modern acoustic imaging technology. A variety of inspection modes, such as vertical, horizontal, and diagonal cross-sections have been presented by employing the focus pathway and image reconstruction algorithm. Images have been reconstructed from the reflected echoes resulting from the change in the acoustic impedance at the interface of the material layers or defects. The results described in this paper indicate that the novel acoustic technology can expand the scope of SAM as a versatile diagnostic tool requiring less time and having a high efficiency.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2013년도 춘계학술대회 논문집
• /
• pp.917-918
• /
• 2013

• 한국광학회:학술대회논문집
• /
• 한국광학회 2007년도 하계학술발표회 논문집
• /
• pp.185-186
• /
• 2007

• 한국정밀공학회지
• /
• 제24권4호
• /
• pp.21-28
• /
• 2007

• 한국광학회:학술대회논문집
• /
• 한국광학회 2008년도 동계학술발표회 논문집
• /
• pp.239-240
• /
• 2008

• 한국광학회:학술대회논문집
• /
• 한국광학회 2006년도 하계학술발표회 논문집
• /
• pp.231-232
• /
• 2006