• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.123-123
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• 2013

OCT (Optical Coherence Tomography)는 의료용 생체조직의 단층 영상을 레이저 빛을 이용하여 구현하는 첨단 의료기술이다. Time-domain과 Fourier-domain을 기반으로 다양한 광간섭 신호의 획득이 연구되고 있으며, 영상획득 속도의 향상을 위한 경쟁이 세계적으로 치열한 상황이다. 최근 초고속 파장훑음 광원(Wavelength-swept source)의 개발을 통하여 초당 300 frame 이상의 단층 영상이 구현되고 있다. 본 발표에서는 초고속 파장훑음 레이저 광원(Wavelength swept laser)이 능동형 모드잠금(Active mode locking) 외부공진 반도체 공진 구조를 기반으로 새롭게 구현된 연구 성과를 포함한다. 분산에 의한 모드 잠금에 의하여 발진 파장이 결정되어 가변하므로 1 MHz 급 이상의 초고속 반복이 가능하며, 특히 의료용 산업용 분야의 다양한 광센서 및 광영상 응용에 활발히 응용되고 있다.

• Korean Journal of Optics and Photonics
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• v.28 no.1
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• pp.22-27
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• 2017

Time-encoded near-infrared spectroscopy (NIRS) system is proposed, based on a near-infrared (NIR) swept laser source, for comparison to the conventional NIRS method using a detector-type spectrometer. The cavity of the NIR swept laser source consists of a semiconductor optical amplifier (SOA) with a gain region around 800 nm, and several fiber-optic components. To change the output wavelength in time using an applied electric radio-frequency signal, an acousto-optic tunable filter (AOTF) is introduced in the fiber ring cavity configuration. To demonstrate the feasibility of an NIR swept laser source for NIRS imaging, the spectroscopic comparison of two kinds of absorbance-measuring systems a detector-type spectrometer using a white light source, and a source-type spectrometer using an NIR swept laser is successfully performed with an NIR-absorbing dye.

• Electronics and Telecommunications Trends
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• v.39 no.1
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• pp.48-61
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• 2024

The integration of high-capacity terrestrial networks with non-terrestrial communication using satellites has become essential to support seamless low-latency services based on artificial intelligence and big data. Tunable light sources have been instrumental in resolving the complexity of channel management in wavelength division multiplexing (WDM) systems, contributing to increased network flexibility and serving as optical sources for long-distance coherent systems. Recently, these light sources have been applied to beam-steering devices in laser communication and sensing applications across ground, aerial, and satellite transport. We examine the utilization and requirements of tunable lasers in WDM networks and describe the relevant development status. In addition, performance requirements and development directions for tunable lasers used in optical interference systems and beam-steering devices are reviewed.