FEL2011 - List of Authors (Song, Y.)

Paper	Title	Page
FROA3	Sub-100-attosecond Timing Jitter Ultrafast Fiber Lasers for FEL Optical Master Oscillators	648
	J. Kim, K. Jung, C. Kim, H. Kim, T.K. Kim, S. Park, Y. Song, H. Yang KAIST, Daejeon, Republic of Korea
	Funding: Pohang Accelerator Laboratory and NRF of Korea (2010-0003974) Future FELs require femtosecond and even sub-femtosecond timing precision over the entire facility. To meet this timing demand, optical techniques based on modulated cw lasers or ultrafast pulsed lasers have been investigated intensively. It has recently been shown that the timing system based on ultrafast fiber lasers and timing-stabilized fiber links enables long-term stable, sub-10-femtosecond level synchronization []. In order to achieve sub-femtosecond level synchronization, the optimization of timing jitter in ultrafast fiber lasers is required. In this work, by operating the fiber lasers at close-to-zero intracavity dispersion, we optimize the timing jitter of ultrafast fiber lasers toward sub-femtosecond level for the first time. The measured timing jitter of 80 MHz Er-fiber and Yb-fiber lasers is 100 attosecond and 185 attosecond, respectively, when integrated from 10 kHz to 40 MHz (Nyquist frequency) offset frequency. To our knowledge, this is the lowest high-frequency timing jitter from ultrafast fiber lasers so far. The sub-100-attosecond timing jitter from optical master oscillators is the first step toward attosecond-precision FEL timing systems. [1] J. Kim et al, "Drift-free femtosecond timing synchronization of remote optical and microwave sources," Nature Photonics 2, 733-736 (2008).*

Paper

Title

Page

Sub-100-attosecond Timing Jitter Ultrafast Fiber Lasers for FEL Optical Master Oscillators

648

J. Kim, K. Jung, C. Kim, H. Kim, T.K. Kim, S. Park, Y. Song, H. Yang
KAIST, Daejeon, Republic of Korea

Funding: Pohang Accelerator Laboratory and NRF of Korea (2010-0003974)
Future FELs require femtosecond and even sub-femtosecond timing precision over the entire facility. To meet this timing demand, optical techniques based on modulated cw lasers or ultrafast pulsed lasers have been investigated intensively. It has recently been shown that the timing system based on ultrafast fiber lasers and timing-stabilized fiber links enables long-term stable, sub-10-femtosecond level synchronization [*]. In order to achieve sub-femtosecond level synchronization, the optimization of timing jitter in ultrafast fiber lasers is required. In this work, by operating the fiber lasers at close-to-zero intracavity dispersion, we optimize the timing jitter of ultrafast fiber lasers toward sub-femtosecond level for the first time. The measured timing jitter of 80 MHz Er-fiber and Yb-fiber lasers is 100 attosecond and 185 attosecond, respectively, when integrated from 10 kHz to 40 MHz (Nyquist frequency) offset frequency. To our knowledge, this is the lowest high-frequency timing jitter from ultrafast fiber lasers so far. The sub-100-attosecond timing jitter from optical master oscillators is the first step toward attosecond-precision FEL timing systems.
[1] J. Kim et al, "Drift-free femtosecond timing synchronization of remote optical and microwave sources," Nature Photonics 2, 733-736 (2008).