• Title/Summary/Keyword: Optical recording system

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Magneto-Optical Recording in Near-Field using Elliptic Solid Immersion Lens (타원형 고체잠입렌즈를 이용한 근접장 광자기 기록)

  • 박재혁;이문도;박노철;박영필
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2003.06a
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    • pp.678-681
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    • 2003
  • In conventional optical data storage numerical aperture (NA) cannot be over 1 because of diffraction limit. To overcome this limitation. solid immersion lens(SIL) have produced a great interest in near-field optical data storage. In conventional optical recording method, the dual lens system using object lens and SIL had been studied generally. But the conventional SIL system has some critical problems that must be solved. The problems are heat, contamination. alignment of optical components and so on. To solve these problems. this work proposes enhanced SIL which has several advantages for mechanical and optical issues. This new SIL system named elliptic SIL(ESIL) can use evanescent energy in near-field more effectively. In addition. because of applying the inside recording unlike previous surface recording, ESIL can clear up the problems. The design and analysis of ESIL art executed by using CODE V. Also, in this paper we composed actual data recording system and achieved recording experiment by applying ESIL to magneto-optical recording. In conclusion. we analyze the improvement of aerial density and the reasonability of application to real data storage system.

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Design and Evaluation of An Electromagnetic Driven Actuator for Near-field Optical Recording System (근접장 광기록 시스템용 전자기구동 액추에이터의 설계 및 평가)

  • 김석중;이용훈;이철우;서중언
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.24 no.11
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    • pp.2732-2741
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    • 2000
  • Combination of magnetic recording technology and optical recording technology such as Near Field Optical Recording is watched recently. In order to accomplish this technology, the development of an electromagnetic driven mm-sized mirror shifting laser beam in track direction have to needed. In Near Field Optical Recording System, shifting laser beam in track direction mean as fine tracking and means as coarse tracking. Therefore in Near Field Optical Recording, 2-stage actuator is composed of servo controller in reading or recording information on disc layer. In our research, through design and simulation process of driven mm-sized mirror, we arrange systematically design process of driven mm-sized mirror having good frequency transfer characteristics. Design and simulation processes included modal analysis of spring, calculation of magnetic moment according to the number of turns and geometric configuration of coil and magnetic circuit analysis meaning that calculation of magnetic flux density in air gap of magnetic circuit. After that we design and make parts of driven mm-sized mirror, assemble and evaluate our electriomagnetic driven mm-sized mirror. we compared design values with actual characteristic values and present solution scheme. Through these processes we performed manufacturing of an electromagnetic driven mm-sized mirror having good frequency-domain characteristics and high sensitivity characteristics.

Analysis of error correction capability and recording density of an optical disc system with LDPC code (LDPC 코드를 적용한 광 디스크 시스템의 에러 정정 성능 및 기록 용량 분석)

  • 김기현;김현정;이윤우
    • Proceedings of the IEEK Conference
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    • 2003.11a
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    • pp.537-540
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    • 2003
  • In this paper, we evaluated error correction performance and recording density of an optical disc system. The performance of Low-Density Parity Check code (LDPC) is compared to the HD-DVD (BD) ECC. The recording density of optical disc can be increased by reducing the redundancy of the user data. Moreover, since the correction capability of LDPC with decreased redundancy is better than that of BD, the recording density can also be increased by reducing the mark length of the data on the disc surface.

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Holographic optical security system using a reflection photopolymer (반사형 포토폴리머를 이용한 홀로그래픽 광 보안 시스템)

  • Sin, Chang-Won;Kim, Nam;Kim, Min-Su;Jeon, Seok-Hui;Kim, Eun-Gyeong
    • Proceedings of the Optical Society of Korea Conference
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    • 2008.02a
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    • pp.199-200
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    • 2008
  • In this paper, we researched optical characteristics of a holographic optical security system using a reflection recording material and optical random phase mask. The system have the property of optical security key with the phase mask. Also, a reflection recording geometry can reduced a size of the reconstruction system because a input beam to reconstruct a holographic image and a diffraction beam are the same side on the material.

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Investigation of Interface between Slider and Plastic Disk for Optical Head (Optical head를 고려 한 slider와 plastic disk의 interface에 대한 연구)

  • 박진무;정구현;김대은
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 2000.11a
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    • pp.193-198
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    • 2000
  • Near-field recording NFR), advanced optical storage technology, relies on maintaining a small gap between the optical head and the media. This can be accomplished by utilizing the flying optical head concept as in the magnetic recording. In this research, slider/suspension system and plastic disk are tested for their head/disk interface performance. CSS tests are conducted to monitor the frictional and flying characteristics of sliders.

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A Study on Assembly and Evaluation of SIL optical Head for surface Recording of SIL based NFR (고체침지렌즈 기반 근접장 표면 기록을 위한 고체침지렌즈 광학 헤드의 조립 및 평가에 대한 연구)

  • Min, Cheol-Ki;Kim, Tae-Seob;Yoon, Yong-Joong;Park, No-Cheol;Park, Young-Pil
    • Transactions of the Society of Information Storage Systems
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    • v.4 no.1
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    • pp.19-22
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    • 2008
  • For the assembly and evaluation of solid immersion lens (SIL) optical head which is the key component of SIL based near field recording (NFR) technology, we modify the Twyman-Green interferometer. Super-hemisphere SIL optical head for the surface recording is assembled and evaluated by the modified Twyman-Green interferometer. In order to verify the optical performance of the assembled SIL optical head, we compare the measured results of the SIL optical head with the simulation ones. Finally, we show the feasibility of applying the assembled SIL optical head to near field recording system by the experiment of the dynamic gap control based on test bed.

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Intermediate Holographic Data Storage System by Using Sequentially Superimposed Recording

  • Yi, Jong-Su;Lee, Yeon-Ho
    • Journal of the Optical Society of Korea
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    • v.13 no.4
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    • pp.456-463
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    • 2009
  • We introduce a holographic data storage system for intermediating between small data sets and mass holographic data recording. It employs a holographic sequentially superimposed recording technique. We discuss a time scheduling technique for making uniform reconstruction of sequentially recorded holograms and we show experimental results. We also discuss the Bragg selectivity of sequentially recorded holograms. The maximum storage density of our system is estimated to be 224kbit/$mm^2$. Our system is useful as an intermediate recording system before recording mass holographic data in a larger system.

A Study on the Evaluation of the Optical Head of a Near-field Optical Recording System and Interference Pattern Analysis (근접장 광기록 헤드의 광학적 성능 평가와 정렬 오차에 대한 간섭 무늬 패턴 분석에 대한 연구)

  • Yoon Hyoung Kil;Gweon Dae Gab;Lee Jun Hee;Jung Jae Hwa;Oh Hyung Ryeol
    • Journal of the Korean Society for Precision Engineering
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    • v.22 no.5 s.170
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    • pp.80-86
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    • 2005
  • Optical performance evaluation results and an interference fringe pattern analysis of alignment errors for an optical head of a near-field receding (NFR) system are presented. The focusing unit is an optical head of a NFR system and is composed of a solid immersion lens (SIL) and an objective lens (OL). Generally, the size of the focusing unit is smaller than that of the conventional optical recording head. Hence there are difficulties to assemble the small focusing unit precisely. We composed an evaluation system with an interferometer and evaluated some focusing unit samples aligned and assembled by manual and present the obtained results. Using the conventional optical tool, Code V, a tolerance analysis of the alignment error between the SIL and the objective lens and an interference pattern analysis for the assembly error are executed. Then, through an analysis of the simulation results, the conceptual auto-alignment methodology using a neural network approach is considered.

Scanning Probe Microscopy Study on the Degradation of Optical Recoding Disks by Environmental Factors (광디스크의 노화에 관한 주사 탐침 현미경 연구)

  • Yoon, Man-Young;Shin, Hyun-Chang
    • Journal of the Korean Graphic Arts Communication Society
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    • v.29 no.3
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    • pp.97-104
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    • 2011
  • The storing ability of information of optical disks directly depends on the physical property of recording unit cells. It means that the degradation of optical disks ultimately causes the loss of the physical and chemical properties of recording unit cells and leads also information, too. We investigated the degradation and life time of optical disks which tell us the longevity of the preservation of information. Optical disks were aged using the accelerated aging system and studied by optical reflectivity spectroscopy and atomic force microscopy(AFM), and the preservation environment of electronic media in National central library of Korea also were analysed. Results show that the double reflective coated optical disks have good preservation of recording information but revealed some deformation of dye area in the AFM images. It means that we should include the mechanical and chemical degradation of the optical disks in the life time expectation evaluation.

Optical Cap Sensor for Magneto-Optic Near-Field Recording (MO 근접장 기록을 위한 광학 갭 센서)

  • Yoon, Yong-Joong;Park, Jae-Hyuk;Park, No-Cheol;Park, Young-Pil
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.28 no.3
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    • pp.245-250
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    • 2004
  • This paper proposes a new method of measuring an air interface distance between a solid immersion lens(SIL) applied magneto-optic technology and the disk surface. For applying near-field recording (NFR) technology to the magneto-optic storage devices for the next generation, it is positively necessary to maintain the small air gap under about 100㎚. We design an apparatus that consists of some optical components such as a prism, a polarizer and an analyzer. By using the Fresnel reflection coefficient equation, Jones matrices calculation and Malus's law, we establish a mathematical model for understanding the characteristics of the system. The simulations are based on the mathematical model and through the simulation results which is made with various cases we can estimate the performance of the new optical gap sensor system. Experimental results, which are also based on the mathematical model for specific cases, are in good agreement with simulated ones and demonstrate the possibility as the new optical gap sensor.