A5042848086- Photonic Crystal and Fiber Optics
- Advanced Fiber Laser Technologies
- Optical Coherence Tomography Applications
- Advanced Fiber Optic Sensors
- Optical measurement and interference techniques
- Solid State Laser Technologies
- Laser-Matter Interactions and Applications
- Advanced Measurement and Metrology Techniques
- Advanced Fluorescence Microscopy Techniques
- Structural Health Monitoring Techniques
- Optical Systems and Laser Technology
- Laser Material Processing Techniques
- Spectroscopy Techniques in Biomedical and Chemical Research
- Microfluidic and Bio-sensing Technologies
- Advanced Photonic Communication Systems
- Optical Network Technologies
- Photoacoustic and Ultrasonic Imaging
- Orbital Angular Momentum in Optics
- Optical Wireless Communication Technologies
- Microfluidic and Capillary Electrophoresis Applications
- 3D Printing in Biomedical Research
- Advanced Optical Sensing Technologies
Gwangju Institute of Science and Technology
2019-2023
Korea Photonics Technology Institute
2018-2020
Harvard University
2014-2017
Seoul National University
2012
Innovations in laser engineering have yielded several novel configurations for high repetition rate, broad sweep range, and long coherence length wavelength swept lasers. Although these lasers enabled performance frequency-domain optical tomography, they are typically complicated costly many require access to proprietary materials or devices. Here, we demonstrate a simplified ring resonator configuration that is straightforward construct from readily available at low total cost. It was by an...
Retrieving modal contents from a multimode beam profile can provide the most detailed information of beam. Numerical decomposition is method retrieving contents, and it has gained significant attention owing to its simplicity. It only requires measured an algorithm. Therefore, complicated setup not necessary. In this study, we conceived that be notably improved by data-efficiently sub-sampling image instead using full pixels profiler. By investigating window size, number pixels, algorithm...
Improving the axial resolution by providing wider bandwidth wavelength swept lasers remains an important issue for optical frequency domain imaging (OFDI).Here, we demonstrate a wide tuning range, all-fiber laser at center of 1250 nm combining two ring cavities that share single Fabry-Perot tunable filter.The contain semiconductor amplifiers with central wavelengths 1190 and 1292 nm, respectively.To avoid disturbing interference effects in overlapping spectral region, modulated order to...
Fiber-based polarization-sensitive optical frequency domain imaging is more challenging than free-space implementations. Using multiple input states, fiber-based systems provide sample birefringence information with the benefit of a flexible arm but come at cost increased system and acquisition complexity, either reduce speed or require bandwidth. Here we show that calibration single polarization state, configurations can approach conceptual simplicity traditional configurations. We remotely...
We present a polarization-maintained (PM), narrow-linewidth, ytterbium (Yb)-doped all-fiber amplifier with the result of continuous-wave 818 W, 85.2% slope efficiency, single-mode beam quality and 13 dB polarization extinction ratio. It is based on 6.6 GHz pseudo-random binary sequence (PRBS) phase modulation (<7 full width half maximum (FWHM) laser linewidth) in simple, three-staged master oscillator power configuration. The demonstrates highest output per linewidth ratio kW regime...
We propose a globally optimized stochastic parallel gradient descent (SPGD) algorithm to analyze the modal content of laser beams with high precision.Modal decomposition (MD) based on conventional SPGD algorithms often falls local minimum when beam consists six or more fiber eigenmodes, which results in false combination modes.While keeping simplicity and speed advantages algorithm, we adopted several optimization techniques discern global from minima achieve better accuracy.The enhanced...
By including the additional variable, degree of coherence (DOC) in stochastic parallel gradient descent (SPGD) algorithm, we could improve accuracy modal decomposition which satisfies both measured near-field and far-field laser beams.
We present a high-power, nanosecond 630 nm beam generation based on Raman conversion and second-harmonic (SHG). 116.2 W, single-mode 1080 fiber laser 10/125 µm optical is used as pump source for the 1260 seed diode helps amplification of third-order conversion, which results in 63.7 W at with 54.8% efficiency. SHG to type-I noncritical phase-matching conditions bismuth triborate (BIBO) nonlinear crystal. The average power 15.5 repetition rate 9.26 MHz, pulse width 16.0 ns, efficiency 24.4%....
In clinical and biological fields, circulating tumor cells (CTCs) attracts much attention for the valuable information about cancer progression, status, prognosis after treatment with metastatic cancer. Recently, many researchers have studied to count CTCs efficiently. Representative methods of CTC detection are immune-reaction based method morphology-based method. However, is weak due imperfect markers, has a defect because unclear criterion. this paper, we described system on flow...
200W 532nm single-mode ns-laser with 10MHz-repetition-rate was developed by second-harmonic generation of 1064nm fiber laser. 60% conversion efficiency achieved in a single-pass scheme increasing the effective interaction volume between light and crystal.
Analyzing modal contents of arbitrary beams from optical fiber provides useful information for high-power laser and mode-division-multiplexed communication. Numerical decomposition can be applied to diverse applications universally without complicated setup, but often leads a false solution which is called as local minimum. We propose several ways solve this issue compare the results find best way global optimization based on stochastic parallel gradient descent algorithm.