(Frequency-resolved optical-gating) FROG (Frequency-resolved optical-gating)

FROG 방법 Polarization Gate (PG FROG) Self-Diffraction (SD FROG) (D.J.Kane and R.Trebino Opt. Lett. 18, 823-825) Self-Diffraction (SD FROG) (D.J.Kane and R.Trebino IEEE J.Quntum Electron. 29, 571-579) SHG FROG (K.W.DeLong, R.Trebino, and W.E.White J.Opt.Soc.Am.B 11,2206-2214)

PG FROG *Rhodamine6G dye laser ~620nm <100fs pulses at ~100MHz Imaging Spectrometer (chromex fF250) CCD Camera Gate pulse (45 degree polarization) Probe pulse E(t) Cylindrical lens Nonlinear medium(3mm BK7) Imaging lens (images line focus of beams at nonlinear medium onto slit of spectrometer) *Rhodamine6G dye laser ~620nm <100fs pulses at ~100MHz And a 10Hz Nd:YAG-pumped dye amplifier ~300fs ,~200 *beam splitting yielded two pulses, of 5- and 9- . *10cm focal-length quartz cylindrical. *A spherical lens imaged the signal beam onto the 50 slit of a ¼-m chromex imaging spectrometer. *two-dimensional array photometrics CCD camera

Chirp pulse Linear chirp pulse Positive chirp negative chirp

* The measured signal IFROG or FROG trace * Signal pulse electric field * The measured signal IFROG or FROG trace *The FORG trace can be considered a spectrogram of the E(t)

PG FROG

Two-dimensional phase-retrieval problem

Iterative-Fourier transform algorithm (k+1)st iteration for E(t)

Instantaneous frequency Linear chirp Phase Instantaneous frequency Derived intensity and phase Experimental FROG trace for a linearly chirped pulse

Intensity Autocorrelation

FROG 는 Intensity I(t) 와 Phase 를 측정할 수 있다. FROG Setting을 쉽게 할 수 있다. 결론 FROG 는 Intensity I(t) 와 Phase 를 측정할 수 있다. FROG Setting을 쉽게 할 수 있다. Reference R.Trebino and D.J.Kane J.Opt.Soc.Am.A 10,1101-1111 D.J.Kane and R.Trebino Opt. Lett. 18, 823-825 Ultrashort Laser pulse Phenomena J.C.Diels and W Rudolph. (1996)

Intensity autocorrelation