• Smart Media Journal
• /
• v.7 no.3
• /
• pp.29-34
• /
• 2018

This paper presents a study on adapting optical communication technology using infrared ray for the enhancement of hearing aids in noisy environment. The transmitter module containing microphone and infrared ray-emitting diode converts audio signal to infrared optical signal and sends it out in the air. The receiver module located in a distance receives the infrared signal, converts it to electrical signal, and transfers it to an input of a digital hearing aid. Especially, the receiver module needs to be small, low voltage, and consume low power since it will be attached to hearing aids. Experiments with applying infrared communication technology of digital modulation method and analog non-modulation method show that the analog non-modulation method is adequate for infrared communication of approximately 5m distance indoor. Prototypes of transmitter module and receiver module were manufactured, and internal parameters of the digital hearing aid were adjusted to confirm normal transmit-receive operation of audio signals.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.46 no.8
• /
• pp.12-17
• /
• 2009

We have implement어 a bust mode optical transmitter using digital temperature compensation architecture with a microprocessor. Instead of previous analog real time technique, we used digital sampling and holding technique for the temperature compensation in order to get stable high speed data transmission of the laser diode. This digital temperature compensation technique should be complemented the previous analog method with accuracy and effectiveness in the over Gb/s transmitting application.

• Current Optics and Photonics
• /
• v.6 no.1
• /
• pp.51-59
• /
• 2022

Holographic display technology is one of the promising 3D display technologies. However, the large amount of computation time required to generate computer-generated holograms (CGH) is a major obstacle to the commercialization of digital hologram. In various systems such as multi-depth head-up-displays with hologram contents, it is important to transmit hologram data in real time. In this paper, we propose a rapid CGH computation method by applying an arraying of a down-scaled hologram with the multiplication of a shifted concave lens function array. Compared to conventional angular spectrum method (ASM) calculation, we achieved about 39 times faster calculation speed for 3840 × 2160 pixel CGH calculation. Through the numerical investigation and experiments, we verified the degradation of reconstructed hologram image quality made by the proposed method is not so much compared to conventional ASM.

• Journal of Electrical Engineering and Technology
• /
• v.7 no.5
• /
• pp.784-788
• /
• 2012

In this paper, a high-performance optical gating in a junction device based on a vanadium dioxide dioxide ($VO_2$) thin film grown by a sol-gel method was experimentally demonstrated by directly illuminating the $VO_2$ film of the device with an infrared light at ~1554.6 nm. The threshold voltage of the fabricated device could be tuned by ~76.8 % at an illumination power of ~39.8 mW resulting in a tuning efficiency of ~1.930 %/mW, which was ~4.9 times as large as that obtained in the previous device fabricated using the $VO_2$ thin film deposited by a pulsed laser deposition method. The rising and falling times of the optical gating operation were measured as ~50 ms and ~200 ms, respectively, which were ~20 times as rapid as those obtained in the previous device.

• Korean Journal of Optics and Photonics
• /
• v.23 no.5
• /
• pp.189-196
• /
• 2012

A floating optical system is a system that moves more than 2 groups to focus at the camera lens. At the camera optics, the floating system that is mainly used is an optical system such as a macro lens which changes magnification very much. When the floating system is assembled and fabricated in the factory, there are differences between the image plane of the sensor and the focal plane of the infinity or macro state. Therefore, in a considerable proportion of cases, the focus adjustment to minimize the difference of BWD(Back Working Distance) is carried out in the process of manufacturing. In this paper, in order to decide the movement of each group in a floating system, we evaluated the rotation angle of CAM for the focus adjustment. We know that the maximum magnification of macro state is corrected by this numerical method for the focus adjustment, too. We investigated the limit of CAM rotation angle of the system by using statistical analysis for CAM rotation angle, which uses the focus adjustment of the floating system with symmetric error factors.

• Proceedings of the IEEK Conference
• /
• 2002.07b
• /
• pp.880-883
• /
• 2002

We propose an effective wavelength converter method using frequency shifter for photonic node, and examine the scalability of Generalized Multiprotocol Label Switching (GMPLS) networks. The ana1ysis is examined based on signal to noise ratio (SNR) for present 2.4 and 10 Gbit/s Synchronous Digital Hierarchy (SDH) networks, and next generation 2.7 and 10.8 Gbit/s Optical Transport Networks (OTN) format The proposed 100 channels GMPLS networks using optical frequency shifters are shown to be applicable to transmission network spanning over 1206 km(24 nodes) in 2.7 Gbit/s trunk networks. Transmission over more than 310 km (6 nodes) is also possible in 2.7 Gbit/s Metroporitan Area Networks(MAN).

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1996.11a
• /
• pp.351-355
• /
• 1996

In optical disc system, lens actuator of 4-wire has unwanted moment which occurs tilt. The moment around the axis pallet to the tangential direction of the disk occurs to the moving part. when the moving part is moved in tracking direction and focus driving force is applied. This paper analyzed coupled effect due to the moment based on structural analysis and magnetic field analysis, both using finite element method.

• Journal of the Optical Society of Korea
• /
• v.13 no.4
• /
• pp.464-467
• /
• 2009

The grating projection method with phase-shifting technique is very useful in measuring the 3-dimensional (3D) shape with high accuracy and speed. In this work, we have developed an ultra high-speed digital laser grating projection system using a high-power laser diode and a highsensitivity CMOS camera. With our system, the optical measurement required to find out the profile of a 3D object could be carried out within 2.6 ms, which is a significant ($\sim$10 times) improvement compared with those of the previous studies.

• Journal of the Korean Institute of Telematics and Electronics A
• /
• v.31A no.8
• /
• pp.26-33
• /
• 1994

Optical adders using a modified signed-digit(MSD) number system have been proposed to restrict the carry propagation chain encountered in a conventional binary adder to two positions to the left. But, MSD number system must encode three different states to represent the three possible digits of MSD. In this paper, we propose the design of an optical adder based on 1-bit addition rules by using the method of symbolic substitution (SS). We show that this adder can use binary input which is used by a digital computer, as it is and be implemented by smaller system in size than MSD adder.

• Journal of the Korean Society for Precision Engineering
• /
• v.15 no.7
• /
• pp.52-60
• /
• 1998

In optical disc system, 4-wire actuator has undesired tilt which degenerates the performance of RF signal. This tilt occurs from moment around the axis parallel to the tangential direction of the disk. The main reason of the moment is the coupling effect between focus driving system and tracking driving system. This paper constructed tilt mechanism and analyzed tilt quantity due to the moment based on structural analysis and magnetic field analysis. And the experiment about tilt was executed. The results were compared and discussed about the difference. Then, the design method for reducing tilt angle was suggested.