Hernández-Garay M P, Martínez-Matos O, Izquierdo J G, Calvo M L, Vaveliuk P, Cheben P, Bañares L
Departamento de Óptica, Facultad de Ciencias Físicas, Universidad Complutense de Madrid, Madrid, Spain.
Opt Express. 2011 Jan 17;19(2):1516-27. doi: 10.1364/OE.19.001516.
The majority of the applications of ultrashort laser pulses require a control of its spectral bandwidth. In this paper we show the capability of volume phase holographic gratings recorded in photopolymerizable glasses for spectral pulse reshaping of ultrashort laser pulses originated in an Amplified Ti: Sapphire laser system and its second harmonic. Gratings with high laser induce damage threshold (LIDT) allowing wide spectral bandwidth operability satisfy these demands. We have performed LIDT testing in the photopolymerizable glass showing that the sample remains unaltered after more than 10 million pulses with 0,75 TW/cm2 at 1 KHz repetition rate. Furthermore, it has been developed a theoretical model, as an extension of the Kogelnik's theory, providing key gratings design for bandwidth operability. The main features of the diffracted beams are in agreement with the model, showing that non-linear effects are negligible in this material up to the fluence threshold for laser induced damage. The high versatility of the grating design along with the excellent LIDT indicates that this material is a promising candidate for ultrashort laser pulses manipulations.
超短激光脉冲的大多数应用都需要控制其光谱带宽。在本文中，我们展示了在可光聚合玻璃中记录的体相位全息光栅对源自钛宝石放大激光系统及其二次谐波的超短激光脉冲进行光谱脉冲整形的能力。具有高激光诱导损伤阈值（LIDT）且允许宽光谱带宽操作的光栅满足了这些需求。我们在可光聚合玻璃中进行了LIDT测试，结果表明，在1kHz重复频率下以0.75TW/cm²的功率照射超过1000万个脉冲后，样品仍未改变。此外，我们还开发了一个理论模型，作为科格尔尼克理论的扩展，为带宽操作提供关键的光栅设计。衍射光束的主要特性与模型相符，表明在达到激光诱导损伤的fluence阈值之前，这种材料中的非线性效应可以忽略不计。光栅设计的高度通用性以及出色的LIDT表明，这种材料是用于超短激光脉冲操纵的有前途的候选材料。
