AOP 2016 
Research Day 2016 
OSK 2016 
Sci Rep 2015 
COOC 2015 
KAIST-Kyushu 2014 
OSK Tutorial 2014 
OSK 2013 
PC 2012 
NPhoton Highlight 12 
PC 2010 
LPR cover 
NPhoton News 08 

Prof. Kim published an invited review article at OSA's prestigious journal (Aug 30, 2016)

Prof. Kim, together with a former post-doc Youjian Song, published an invited review article on ultralow-noise mode-locked fiber lasers at Advances in Optics and Photonics (AOP). AOP is a prestigious review journal, published by Optical Society of America (OSA), that is designed to capture the most significant advances in optics and photonics from prominent authors at the forefront of their fields. Prof. Kim's 76-page-long paper comprehensively reviews the principles, implementations and applications of ultralow-noise mode-locked fiber lasers and frequency combs over the last 25 years. This paper has been one of the top 10 downloaded AOP articles for 5 months in a row (Sep 2016 - Jan 2017), and was also selected as one of the top downloaded articles in lasers and laser optics from AOP and OL in 2016.
For further reading:
  • J. Kim and Y. Song, "Ultralow-noise mode-locked fiber lasers and frequency combs: principles, status and applications," Adv. Opt. Photon. 8, 465-540 (2016)

    Prof. Kim is awarded 2015 KAIST Top 10 R&D Achievements Award (May 24, 2016)

    Our work on ultralow-noise fiber photonic oscillators was selected as one of the Top-10 R&D Achievements of KAIST in 2015. This work showed a low-cost and robust all-fiber photonic way to achieve world-class timing noise and stability, which can be readily applied in signal generators, scientific facilities, and defense systems. The prize was awarded at the annual KAIST Research Day ceremony held on May 24, 2016.

    Junho Shin is awarded Outstanding Paper Award from OSK Meeting (Jan 22, 2016)

    Our recent paper "Femtosecond-stability timing link stabilization method" is awarded Outstanding Student Paper Award from Optical Society of Korea (OSK) Winter Meeting 2016 held in Daejeon, Jan 20-22, 2016.

    This work demonstrated the method for stabilizing timing links in a long-term stable way using PZTs and motorized stages. This research was performed by a collaboration with the Time-Frequency Center of Korea Research Institute for Standards and Science (KRISS).

    Congratulations Junho!

    Ultralow-noise all-fiber oscillator work was covered by national news media (Nov 12, 2015)

    Our recent work on ultralow-noise, all-fiber photonic clock oscillators (K. Jung and J. Kim, "All-fibre photonic signal generator for attosecond timing and ultralow-noise microwave," Sci. Rep. 5, 16250 (2015)) was covered by major national news media including Chosun Ilbo, YTN, and Yonhap News. We showed a simple and robust way to suppress the phase noise of mode-locked lasers using all-fiber technology, which resulted in only 3-femtosecond absolute timing error accumulated in 0.1-s (which is the definition of timing jitter by ITU Standards). This result will find more applications in precision timing and synchronization, low-noise microwave synthesis, photonics radars, ranging, and optical communications in the near future.
    For further reading:
  • Chosun Ilbo Article ("KAIST researchers developed an ultra-precise timing technology")
  • Yonhap News Article ("New fiber optic clocks show a millionth of a billionth of a second timing error.")
  • YTN TV News ("New fiber optic clocks show equivalent timing error of 1 second in one million years")

    Chan-Gi and Kwangyun are awarded Outstanding Paper Awards from COOC (Jun 4, 2015)

    A pair of papers entitled "Residual phase noise dependence on input power levels in FLOM-PD" (by Chan-Gi Jeon) and "Generation of fiber laser-based ultra-stable optical pulse trains" (by Kwangyun Jung) was each awarded Outstanding Student Paper Awards from Conference on Optoelectronics and Optical Communications (COOC) 2015 held in Busan, Jun 3-5, 2015.

    Chan-Gi's work found the optimal condition to achieve the lowest residual phase noise in laser-microwave synchronization using FLOM-PD device. Kwangyun's work showed a new all-fiber-optic way to stabilize the repetition-rate of mode-locked fiber lasers.

    Congratulations Chan-Gi and Kwangyun!

    Junho Shin is awarded Poster Award from KAIST-Kyushu ME Workshop (Sep 26, 2014)

    Master student Junho Shin was selected as one of four Outstanding Student Poster Award winners of the 7th KAIST-Kyushu University Joint Workshop on Frontiers in Mechanical and Aerospace Engineering 2014 held in Fukuoka, Japan, Sep 25-27, 2014.

    Junho's work entitled "Laser-based technology for controlling accelerator-based light sources" showed the latest advances in achieving femtosecond-stability phase control of RF signals using short-pulse lasers in accelerator environment.

    Congratulations Junho!

    Prof. Kim delivered a tutorial lecture on frequency combs at OSK Meeting (Aug 25, 2014)

    Prof. Kim delivered a special tutorial lecture on frequency combs at Optical Society of Korea (OSK) Annual Summer Meeting 2014 held in Jeju Island, Aug 25-27, 2014. The 2-hour lecture, entitled "Advanced Optical Frequency Combs and Their Ultrahigh-Precision Applications," covered various generation methods of frequency combs and their emerging applications ranging from optical atomic clocks to photonic radars, with more than 200 attendees.

    Kwangyun Jung is selected as IEEE-IFCS Student Paper Competition Finalist (May 22, 2014)

    PhD student Kwangyun Jung was selected as one of the Student Paper Competition Finalists of IEEE International Frequency Control Symposium (IFCS) 2014 held in Taipei, Taiwan, May 19-22, 2014.

    Kwangyun's work entitled "Microwave transfer through optical frequency comb toward 10-19 instability using fiber-loop optical-microwave phase detector " showed a new way for high-precision microwave transfer, with an order of magnitude improved stability performance from the previous works. Kwangyun was a student paper competition finalist in IEEE-IFCS 2013 as well, where he presented a paper on attosecond-stability laser-microwave synchronization.

    Congratulations Kwangyun!

    Heewon Yang is awarded Outstanding Paper Award from OSK Meeting (Feb 20, 2013)

    [Student authors of the paper, Heewon (left) and Chur (right)]
    Our recent paper "GHz repetition rate, diode-pumped Yb:KYW laser mode-locked by a CNT-coated mirror" is awarded Outstanding Student Paper Award from Optical Society of Korea (OSK) Winter Meeting 2013 held in Daejeon, Feb 18-20, 2013.

    This work demonstrated the first GHz repetition rate solid-state laser mode-locked by a CNT saturable absorber.

    This research was performed by a collaboration with Prof. Fabian Rotermund's group at Ajou University and Dr. Guang-Hoon Kim at KERI. The authors were Heewon Yang (PhD student), Chur Kim (PhD student), Sun Young Choi (PhD student at Ajou Univ), Dr. Guang-Hoon Kim, Prof. Fabian Rotermund and Prof. Jungwon Kim.

    Congratulations Heewon and Chur!

    Chur Kim is awarded Outstanding Paper Award from Photonics Conference (Dec 6, 2012)

    [Student authors of the paper, Kwangyun (left) and Chur (right)]
    Our recent paper "Timing jitter and intensity noise in CNT-mode-locked fiber lasers" is awarded Outstanding Student Paper Award from Photonics Conference 2012 held in Pyeongchang, Gangwon-Do, Dec 5-7, 2012.

    This work demonstrated that low intensity noise and timing jitter can be obtained from a soliton all-fiber laser mode-locked by an evanescent-field-coupled CNT saturable absorber.

    This research was performed by a collaboration with Prof. Khanh Kieu's group at the University of Arizona. The authors were Chur Kim (PhD student), Kwangyun Jung (PhD student), Prof. Khanh Kieu and Prof. Jungwon Kim.

    Congratulations Chur and Kwangyun!

    Prof. Jungwon Kim is elevated to Senior Member of IEEE and OSA (May 14, 2012)

    Prof. Kim is elevated to the Senior Member grade of both the Institute of Electrical and Electronics Engineers (IEEE) and the Optical Society of America (OSA). The criteria for elevation to IEEE Senior Member is that the candidate has professional practice for at least 10 years and show significant performance over a period of at least 5 years, with 3 reference letters from current IEEE Fellows. The Senior Member grade is the prerequisite for being nominated as an IEEE Fellow. The criteria for elevation to OSA Senior Member is that the candidate has at least 10 years of well-established professional accomplishment, with 2 reference letters from current OSA members.

    Prof. Jungwon Kim is selected as the Ewon Assistant Professor (March 7, 2012)

    Prof. Kim is appointed as one of the ten Ewon Assistant Professors at KAIST. The Ewon Assistant Professorship is founded to "promote young assistant professors with a significant potential to grow and perform creative teaching and research activities", following the wish of Mrs. Ewon Oh who donated a generous scholarship fund to KAIST in 2010. The appointment term is 3 years (March 2012-February 2015).

    Record-low timing jitter result is highlighted in Nature Photonics (February 1, 2012)

    A recent paper from our group (T. K. Kim et al, "Sub-100-as timing jitter optical pulse trains from mode-locked Er-fiber lasers," Opt. Lett. 36, 4443-4445 (2011)) is selected in the Research Highlights of Nature Photonics. This paper showed a breakthrough in timing jitter of mode-locked fiber lasers, demonstrating unprecedented sub-100-attosecond-level timing jitter in the 1500-1600 nm telecommunication wavelength range. It is expected that such attosecond-level-jitter lasers can be used for the future optical sampling, analog-to-digital conversion, precision network synchronization, and signal characterization.

    For further reading:
  • N. Horiuchi, "Ultrafast photonics: Ultralow timing jitter" Nature Photonics 6, 71 (2012)
  • T. K. Kim et al, "Sub-100-as timing jitter optical pulse trains from mode-locked Er-fiber lasers," Opt. Lett. 36, 4443 (2011)
  • Y. Song et al, "Timing jitter optimization of mode-locked Yb-fiber lasers toward the attosecond regime," Opt. Express 19, 14518 (2011)

    Hyoji Kim is awarded Outstanding Paper Award from Photonics Conference (Dec 2, 2010)

    [Authors of the paper, Kwangyun, Hyoji, Jungwon, Youjian (from left to right), in front of the cross-correlator set-up]
    Our recent paper "Balanced Optical Cross-Correlators for the Timing Jitter Measurement of Ultrafast Yb-Fiber Lasers" is awarded Outstanding Student Paper Award from Photonics Conference 2010 held in Hoengseong, Gangwon-Do, Dec 1-3, 2010.

    This work demonstrated a balanced cross-correlator working at 1-μm, which enabled the timing jitter characterization of Yb-fiber lasers with 24-attosecond (2.4×10-17 s) resolution over the full Nyquist frequency.

    The authors are URP researcher Hyoji Kim, master student Kwangyun Jung, BK21 postdoctoral associate Youjian Song, and Professor Jungwon Kim, all members of UPCaM Group.

    Congratulations Hyoji, Kwangyun and Youjian!

    Recent work is featured on the cover page of Laser and Photonics Reviews (April 23, 2010)

    A recent invited review article by the PI (J. Kim and F. X. Kaertner, "Attosecond-precision ultrafast photonics," Laser and Photonics Reviews 4, 432 (2010)) was selected as the "Editor's Choice" paper and highlighted on the cover page of the April 2010 issue of the journal. This paper outlines our recent progress toward attosecond-timing-precision photonics and its potential applications in high-precision signal generation, synchronization, distribution and characterization. It was also featured by Dr. Fuchs entitled "Ultra-precise and ultra-fast" on MaterialsViews.

    For further reading:
  • Front cover picture abstract of April 2010 issue of Laser and Photonics Reviews
  • Editor's Choice: Attosecond-precision ultrafast photonics
  • "Ultra-precise and ultra-fast"by Dr. G. Fuchs on MaterialsViews

  • Recent work is featured in Nature Photonics and (December 4, 2008)

    A recent paper by the PI (J. Kim et al, "Drift-free femtosecond timing synchronization of remote optical and microwave sources," Nature Photonics 2, 733 (2008)) was highlighted in News and Views of Nature Photonics and in Research News of This paper showed a breakthrough in long-term stable, long-distance synchronization of multiple lasers and electronic sources. The demonstrated techniques pave a way for high-precision clocking of large-scale scientific facilities including next generation light sources (X-ray free-electron lasers).

    For further reading:
  • "Ultrafast optics: Femtosecond timing distribution" by Patrick Gill (in News and Views of Nature Photonics)
  • "Synchronized sources are right on time" by Marie Freebody (in Research News of
  • "Unprecedented accuracy: RLE researchers achieve breakthrough in drift-free timing synchronization" (Press release of the MIT Research Laboratory of Electronics)