Ultrafast Laser Energy Density and Retinal Absorption Cross-Section Determination by Saturable Absorption Measurements

• 作者: Alfons Penzkofer Meike Luck Peter Hegemann Tilo Mathes
• 来源期刊: 分析科学方法和仪器期刊(英文)
• 学科: 化学
• 关键词: Laser Pulse Peak Energy DENSITY DETERMINATION Ground-State ABSORPTION CROSS-SECTION DETERMINATION Excited-State ABSORPTION CROSS-SECTION DETERMINATION Saturable ABSORPTION ADS084BE Dye Histidine Kinase RHODOPSIN HKR1 RETINAL Schiff Base RetA Cofactor Number DENSITY DETERMINATION
• 年，卷（期）: 2014,（1）
• 页码范围: 19-26
• 页数: 8页
• 分类号: O6

摘要

Laser pulse nonlinear transmission measurements through saturable absorbers of known absorption parameters allow the measurement of their energy density. On the other hand, nonlinear transmission measurements of laser pulses of known energy density through absorbing media allow their absorption parameter determination. The peak energy density w0P of second harmonic pulses of a mode-locked titanium sapphire laser at wavelength λP = 400 nm is determined by nonlinear energy transmission measurement TE through the dye ADS084BE (1,4-bis(9-ethyl-3-car-bazovinylene)-2-methoxy-5-(2’-ethyl-hexyloxy)-benzene) in tetrahydrofuran. TE(w0P) calibration curves are calculated for laser pulse peak energy density reading w0P from measured pulse energy transmissions TE. The ground-state absorption cross-section σP and the excited-state absorption cross-section σex at λP, and the number density N0 of the retinal Schiff base isoform RetA in pH 7.4 buffer of the blue-light adapted recombinant rhodopsin fragment of the histidine kinase rhodopsin HKR1 from Chlamydomonas reinhardtii were determined by picosecond titanium sapphire second harmonic laser pulse energy transmission measurement TE through RetA as a function of laser input peak energy density w0P. The complete absorption cross-section spectrum σ