Research On Ultrashort Pulse Measurement With GRENOUILLE

With the wide using of ultrashort pulsed laser in the fields of physics, chemistry, biology, medicine and communications, it received more attention all over the world, so the generation technology of ultrashort pulses is developing rapidly. As the ultrashort pulses is becoming more and more narrow, the measurement techniques of ultrashort pulses require higher resolutions. The method of frequency-resolved optical gating (FROG) is most widely used for measuring femtosecond ultrashort pulses, but this method has a inadequacy that it can not take real-time measurement. The GRating-Eliminated No-nonsense Observation of Ultrafast Incident Laser Light E-fields(GRENOUILLE) described in this article, which is made on the basis of FROG, has solved the problem. It can be used for real-time measurement.The main contents of this dissertation are listed as follows:1. According to the experimental idea of the GRENOUILLE method, the related theory is introduced, as well as the second harmonic generation and the generation of autocorrelation signal.2. Design the experimental program, select the appropriate equipment for optical structures, and give the reason of the equipment selection. Analyze the optical path in the experiment system and explain the meaning of different directions in the trace getting from the experiment. Study the effect of the Fresnel prism and the thick BBO crystal in the system. Calculate the relation of time delay between the two pulses and horizontal locations inside the BBO crystal, as well as the relationship between the exit angle from the BBO crystal and wavelengths.3. Measure ultrashort pulses of different power by the system, analyze the intensity of the trace by using matlab software and draw the three-dimensional intensity distribution of the trace. Finish the trace collection.4. Take the calibration of time delay and wavelength axis of the trace by experimental operation and theoretical calculation. Get the physical values between adjacent pixels along the time delay and wavelength axis, from which we can calculate the information of the ultrashort pulses from the trace.