نوع مقاله : مقاله پژوهشی
نویسندگان
پژوهشکده فوتونیک و فناوریهای کوانتومی، پژوهشگاه علوم و فنون هستهای، سازمان انرژی اتمی، صندوق پستی: 836-14395، تهران- ایران
کلیدواژهها
عنوان مقاله English
نویسندگان English
The experimental investigation of supercontinuum generation in deionized water using an amplified Ti:sapphire femtosecond laser pulses is presented. During the propagation of femtosecond pulses in deionized water, self-focusing leads to filamentation and subsequent supercontinuum generation. The effects of varying the focal point distance from the cell and altering the incident femtosecond laser pulse energy on the supercontinuum spectra were studied. Near critical power, ring and cone emissions contribute significantly to the continuum. The central white light part covers the output signal at very high laser powers. A supercontinuum emission with a bandwidth of 600 nm was achieved using a laser pulse energy of 1.19 mJ. The spectrum broadening, due to Kerr self-focusing and plasma defocusing, was analyzed for 37 femtosecond laser pulses with average powers ranging from 420 to 3800 times the critical power. Increasing the input pulse energy to 460 µJ, corresponding to 2900 times the critical power, resulted in an asymmetric broadening of the spectrum, with the blue edge shifting to 400 nm. Further increases in energy showed no additional shift due to intensity clamping.
کلیدواژهها English