On this basis , a model of pulse damage threshold fth ( j / cm2 ) was proposed . calculations on pulses of three different envelope shapes indicate that , with the same pulse duration , wavelength and incident light intensity , fth of pulse with gaussian envelope is higher that that of the pulses with hyperbolic secant and lorentzian envelope , i . e . gaussian pulse would need a little higher intensity to induce breakdown than the other two 在這個(gè)基礎(chǔ)上,提出了一個(gè)研究脈沖破壞閉值的模型,對三種不同包絡(luò)脈沖的分析表明,在相同的脈寬、波長和入射光強(qiáng)下,高斯脈沖的破壞閉值較高,雙曲正割和洛侖茲脈沖的破壞閩值相對較低,即高斯脈沖最不容易對介質(zhì)造成破壞。
Shapes of pulse envelope are found to have some effect on the degree of phase influences . dependence of single - cycle pulse ( scp ) energy on the carrier phase has been studied for gaussian , lorentzian , hyperbolic secant and sine shapes respectively , which shows that these energies can be expressed in the same form . phase effect on pulse with gaussian envelope is the first to show , then are hyperbolic secant and lorentzian pulses , and sine the last 包絡(luò)對載波相位的作用范圍也是有一定影響的,我們對高斯、洛侖茲、雙曲正割和sinc四種不同包絡(luò)的脈沖,研究了單周期脈沖能量隨載波相位的變化規(guī)律,發(fā)現(xiàn)以上四種脈沖的歸一化能量均可在形式上用同一表達(dá)式表示,并發(fā)現(xiàn)對于這四種不同包絡(luò)的脈沖,高斯脈沖相位的作用最早體現(xiàn)出來,然后是雙曲正割和洛侖茲脈沖, sinc脈沖最遲。
We have calculated and plotted the curves of the refractive index , group velocity index , lowest - order and second - order dispersion indexes as a function of wavelength . the lowest - order and higher - order dispersion - induced broadening and deforming of light pulses is analyzed for various pulse shapes , such as gaussian , super - gaussian and hyperbolic secant pulses 給出了折射率、群速指數(shù)、低階和二階色散系數(shù)隨波長變化的關(guān)系曲線,研究了高斯脈沖、超高斯脈沖和雙曲正割脈沖等超短脈沖在clbo晶體中傳播時(shí),由于低階色散和高階色散引起的脈沖展寬和形變。