• Journal of Korean Ophthalmic Optics Society
• /
• v.7 no.1
• /
• pp.21-23
• /
• 2002

Compared visual acuity that is measured in a artificial myopia with the numerical calculation. Calculation included image's height as well as blur circle that is formed to retina. The blur circle calculated in geometrical optics model, and height of retinal image calculated by refractive power and visual acuity that is measured in a artificial myopia. Define this result as "blur ratio" about blur circle and height of retinal image, and investigated blur ratio relationship about visual acuity in a artificial myopia.

• Journal of the Optical Society of Korea
• /
• v.9 no.3
• /
• pp.87-91
• /
• 2005

The strontium magneto optical trap followed by a Zeeman slower has been demonstrated. The isotope selective characteristics of the trap have been investigated. The fluorescence spectrum of the MOT was compared with those of other high resolution spectroscopic methods. The red detuned deflection beam is also considered for a more selective spectrum.

• Korean Journal of Optics and Photonics
• /
• v.31 no.5
• /
• pp.231-231
• /
• 2020

• Proceedings of the Korean Institute of Communication Sciences Conference
• /
• 2004.11a
• /
• pp.138-138
• /
• 2004

• Journal of Korean Ophthalmic Optics Society
• /
• v.15 no.1
• /
• pp.9-17
• /
• 2010

Purpose: We have studied the problems associated with increased number of ophthalmic optics students and its effects on the supply and demand of optician. Methods: We collected data from Education Statistics, a white paper of Minister for Health, Welfare and Family Affairs, academyinfo web site and University (College) web site. Results: We forecasted an estimate for supply and demand of optician using the entrance number of ophthalmic optics. Conclusions: The numbers of produced optician are in excessive supply. The excessive supply of optician can contribute towards worsening working conditions and lower job satisfaction of an optician. Therefore this can result infrequent turn over of jobs within the same field and migration into the different field of areas. To solve these problems, we will need to act with the manpower policy of government by gathering the voices of the related optician agencies. Then expansion of job domain, improvement of quality level, the improvement of the working conditions for optician can be accomplished by the unification of university system and reduction of entrance numbers for department of ophthalmic optics.

• Journal of the Optical Society of Korea
• /
• v.20 no.4
• /
• pp.500-509
• /
• 2016

Integrating spheres play a central role in the radiometric calibration of remote sensors. With the development of the wide field of view (FOV) remote sensors, aperture diameters of remote sensors are becoming larger and larger. To satisfy the radiometric calibration requirements of full FOV and full aperture, an 8000mm diameter large aperture integrating sphere uniform source with a variable exit port was designed and manufactured. This integrating sphere will be used for pre-launch test and radiometric calibration of remote satellites. In this paper, optical theories were used to design the output spectral radiance. The LightTools software based on ray-tracing simulation method was used to determine the best combination and distribution of inner light sources. A spectral experiment was made to verify the spectral radiance design. To reduce the influence of longtime power-on, a new characteristic measurement method was developed to obtain the radiation characteristic of the integrating sphere, which could greatly improve the measuring efficiency. This method could also be applied to measure other large aperture uniform sources. The obtained results indicate that the spatial uniformity is 98.35%, and the angular uniformity at center position is 98.78%.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.26 no.11
• /
• pp.1012-1019
• /
• 2015

This paper shows the acceleration of iterative physical optics(IPO) for radar cross section(RCS) by using two techniques effectively. For the analysis of the multiple reflection in the cavity, IPO uses the near field method, unlike shooting and bouncing rays method which uses the geometric optics(GO). However, it is still far slower than physical optics(PO) and it is needed to accelerate the speed of IPO for practical purpose. In order to address this problem, graphic processing unit(GPU) can be applied to reduce calculation time and adaptive iterative physical optics-change rate(AIPO-CR) method is also applicable effectively to optimize iteration for acceleration of calculation.

• Journal of the Optical Society of Korea
• /
• v.19 no.6
• /
• pp.695-699
• /
• 2015

A high spectral resolution lidar (HSRL) system based on injection-seeded Nd:YAG laser and iodine absorption filter has been developed for the quantitative measurement of aerosol and cloud. The laser frequency is stabilized at 80 MHz by a frequency locking system and the absorption line of iodine cell is selected at the 1111 line with 2 GHz width. The observations show that the HSRL can provide vertical profiles of particle extinction coefficient, backscattering coefficient and lidar ratio for cloud and aerosol up to 12 km altitude, simultaneously. For the measured cases, the lidar ratios are 10~20 sr for cloud, 28~37 sr for dust, and 58~70 sr for urban pollution aerosol. It reveals the potential of HSRL to distinguish the type of aerosol and cloud. Time series measurements are given and demonstrate that the HSRL has ability to continuously observe the aerosol and cloud for day and night.

• Korean Journal of Optics and Photonics
• /
• v.19 no.3
• /
• pp.187-192
• /
• 2008

The design and analysis of a novel photonic crystal electro-optic modulator are presented in this paper. The device incorporates an electro-optic (EO) polymer slot waveguide into the center of a silicon photonic crystal waveguide. In this device, strong optical confinement in the EO polymer core and small group velocity from the photonic crystal structure provide a surprise enhancement of the EO effect.

• Korean Journal of Optics and Photonics
• /
• v.16 no.1
• /
• pp.50-55
• /
• 2005

A method for measuring the wavefront error and the modulation transfer function(MTF) of large aperture optics using an unequal path interferometer is presented. A bidirectional shearing interferometer is used for collimation testing of the measurement system. A large aperture Fizeau interferometer with long optical path difference measures the wavefront error of the optics under test by using a $\Phi$ 400 mm off-axis parabolic mirror. The MTF is also measured at the wavelength of the interferometer by changing the laser light into partially incoherent light. Test results of a $\Phi$ 300 mm Cassegrain type satellite telescope made in Korea are presented.