• Korean Journal of Optics and Photonics
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• v.11 no.3
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• pp.206-209
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• 2000

A wavelength stabilized high power CW DFB LD module was designed and fabricated for use in externally modulated, Dense Wavelength Division Multiplex (DWDM) systems. A simple, compact wavelength monitoring technology using a thin solid Etalon and PD array assembly was developed for a low cost wavelength stabilized DFB LD module. Also, the excellent module have high power characteristic of 13.5 mW in CW 100 mA current injection with high optical coupling coefficient over 43%. r 43%.

• 전기의세계
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• v.30 no.10
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• pp.655-661
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• 1981

The concentrating solar module with high concentration ratio(320)has been studied.in this paper. The solar module was composed of the EMVJ solar cell, (Fresnel Lens-DCPC)concentrator and heat sink, and was measured by using the PASTF system. The experimental result and the result analysis for the individual item of the module were as f ollows; (1) The conversion efficiency of the module was 8.3%. (2) The optical efficiency of the concentrator was 46.5% (DCPC; 84.8%, Fresnel Lens; 54.8%). (3) The thermal loss of the solar cell was 4.9%. And methods for the further improvement of the concentrating solar module efficiency have been suggested.

• Journal of the Korean Society of Industry Convergence
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• v.23 no.4_2
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• pp.701-708
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• 2020

In this paper, we analyzed the optical properties of the LED module for dental care, which has the effect of promoting cell regeneration and scar treatment. The LED module is a U-shaped module suitable for the shape of teeth. It is manufactured with an LED module (632 nm) and an LED module (632 nm + 870 nm), analyzes the results of optical properties, sets the irradiation distance, irradiation time, and is effective in healing skin wounds. Evaluation was conducted. It was tested in 6 test groups according to the light irradiation conditions, and light was irradiated to the scar site every other day for 7 days, 1 day and 3 days. As a result, it was confirmed that the effect of scar treatment was the highest when the combined wavelength of 632 nm + 870 nm was irradiated in pulse mode than when the single wavelength was irradiated and the composite wavelength was continuously irradiated. In group C group irradiated with PW Mode: pulse mode (period 36 ms, pulse width 35 ms) using a composite wavelength with LED module (632 nm + 870 nm) than group A without light irradiation, the length of scar reduction was 19 %, the area of the scar was further reduced by 10%, and it was confirmed that it is effective in treating scars in the wound area.

• Journal of the Optical Society of Korea
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• v.18 no.4
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• pp.406-413
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• 2014

An optical true-time delay beam-forming system using a tunable dispersion compensating module (DCM) for dense-wavelength division modulation (DWDM) and a multiwavelength fiber ring laser for a phased array antenna is proposed. The multiwavelength fiber ring laser has one output that includes four wavelengths; and four outputs that include only single-wavelength. The advantage of such a multiwavelength fiber ring laser is that it minimizes the number of devices in the phased array antenna system. The time delays according to wavelengths, which are assigned for each antenna element, are obtained from the tunable DCM. The tunable DCM based on a temperature adjustable Fabry-Perot etalon is used. As an experimental result, a DCM could be used to obtain the change of the beam angle by adjusting the dispersion value of the DCM at the fixed lasing wavelengths of the fiber ring laser in the proposed optical true-time delay.

• Journal of IKEEE
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• v.18 no.4
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• pp.603-611
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• 2014

When image sensor and lens are fixed on the module, mechanical errors often induce tilt, rotation, or narrow field-of-view of the acquired image. Therefore, the optical characteristics of image sensor modules should be tested by test equipments. This paper explains how to test the optical characteristics of images sensors. It also proposes the standardized description methods of optical characteristics tests which are similar with those of image acquisition characteristics tests. The proposed method helps the test equipments to perform image acquisition characteristics tests and optical characteristics tests together.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.51.2-51.2
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• 2010

In recently, interests in the New & Renewable Energy are increasing because of exhaustion of fossil energy and limit of greenhouse gas emission all over the world. Furthermore, improvements in living standards and high-raise Buildings due to the industrial growth require a lot of sunlight in the interior space. Sunlight system gets the natural light into the indoor dark space. There are a lot of type of systems which are reflector type, duct type, optical fibers type and so on. And these systems consist of light-collection module, light-transporting module and light-emitting module. In this research, we installed optical fiber sunlight system in our head office building and tested the system's performance and efficiency. Optical fiber sunlight system is closely connected with hour of sunlight, due to the system have to chase the sun for the solar concentrating, and the system's light-collection and light- transporting efficiency is important factors in the system's performance. As a result of the test, system can be used about 5.66 hours on average in a day, and it has a about 3.21 times collection efficiency and 5.5% transmission loss.

• Journal of the Semiconductor & Display Technology
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• v.15 no.4
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• pp.1-9
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• 2016

The warpage on mobile phone camera packages occurs due to the CTE(Coefficient of Thermal Expansion) mismatch between a thin silicon die and a substrate. The warpage in the optical instruments such as camera module has an effect on the field curvature, which is one of the factors degrading the optical performance and the product yield. In this paper, we studied the effect of die bonding epoxy on the package and optical performance of mobile phone camera packages. We calculated the warpages of camera module packages by using a finite element analysis, and their shapes were in good agreement showing parabolic curvature. We also measured the warpages and through-focus MTF of camera module specimens with experiments. The warpage was improved on an epoxy with low elastic modulus at both finite element analysis and experiment results, and the MTF performance increased accordingly. The results show that die bonding epoxy affects the warpage generated on the image sensor during the packaging process, and this warpage eventually affects the optical performance associated with the field curvature.

• International Journal of Internet, Broadcasting and Communication
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• v.10 no.2
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• pp.45-50
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• 2018

Recently the water management department advised the water treatment industry to focus on deploy the chemical free and the environmentally responsible process to adopt on water treatment plants in every country. In this objective, water treatment process started using ultrasonic based phycocyanin extraction with fluorescence measurement techniques to detect the change in the yield of phycocyanin. This paper propose the design of optical filter model for fluorescence technique based immersive optical phycocyanin measurement sensor design. The proposed design uses the multi-wavelength sensor module for irradiating part, and this plays a role of removing a wavelength band other than 590 ~ 620 nm. The preliminary study on immersed phycocyanin sensor, the fluorescence value of picocyanin according to the ultrasonic intensity, treatment time and number of cells was measured using JM phycocyanin module to emulate the proposed design, and were compared performance of the proposed sensor emulation. In this design, the phycocyanin fluorescence value increased about 2.1 ~ 4.7 times as the ultrasonic treatment time increased as compared with JM phycocyanin module, and the phycocyanin fluorescence value within the analysis range was obtained by ultrasonic treatment within one minute.

• Korean Journal of Optics and Photonics
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• v.14 no.5
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• pp.509-514
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• 2003

Mach-Zehnder interferometric wavelength converters with monolithically integrated semiconductor optical amplifiers (SOA's) have been fabricated and characteristics of wavelength conversion at 10 Gb/s have been investigated for wavelength span of 40 nm. The devices have been achieved by using a butt-joint combination of buried ridge structure type SOA's and passive waveguides. In the integration, a new method has been applied that removes p+InP cladding layer leading to high propagation loss and forms simultaneously the current blocking and the cladding layer using undoped InP. The module packaging has been achieved by using a titled fiber array for effective coupling into the tilted waveguide in the wavelength converter. Using the module, wavelength conversion with power penalty lower than 1 ㏈ at 10 Gb/s has been demonstrated for wavelength span of 40 nm. In addition, it is show that the module can provide 2R (re-amplification, re-shaping) operation by demonstrating the conversion with the negative penalty.

• Korean Journal of Optics and Photonics
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• v.10 no.1
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• pp.73-79
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• 1999

Semiconductor optical switch modules of 1$\times$2, 1$\times$4, and 4$\times$4 types for 1550 nm optical communication systems were fabricated by using laser welding technique, embodying in 30-pin butterfly package. For better coupling efficiency between switch chip and optical fiber, tapered fibers of 10~15mm lens radii were used, which provided up to 60% optical coupling efficiency. With the help of new laser hammering process, we could recover the lost optical power almost completely up to average 82% of initially obtained power. The fabricated optical switch modules showed good thermal stability of less than 5% degradation even after 200 times thermal cycling test. The 2.5 Gbps optical transmission characteristics of the 4$\times$4 switch module showed low sensitivities of less than -30dB for all possible switching paths. The transmission penalties of 1$\times$2 switch module at $10^{-10}$ BER were 0.6dB and 0.7dB for 50Xm and 90 Km optical fibers, respectively.