激光烧蚀制备分布反馈式有机激光器件

采用激光烧蚀的方法结合激光全息技术,直接在高分子聚合物MEH-PPV薄膜表面烧蚀光栅结构,制备了分布反馈式有机激光器。这一方法具有工艺简单、光栅参数的可控性和重复性好等优点。器件MEH-PPV的膜厚是400 nm。利用波长为355 nm的Nd-YAG纳秒激光器进行单脉冲烧蚀,获得的光栅周期和光栅高度分别为370 nm和 100 nm。利用飞秒激光放大器作为泵浦源激射DFB激光器件,得到激射阈值约为182 μJ·cm^-2·pulse^-1,光谱的波峰约在609 nm处,半高宽为4.2 nm。通过改变两光束的夹角获得了周期为360, 370, 380, 390 nm的光栅,它们对应的激光波峰分别为602.91, 609.24, 613.26, 619.01 nm。

Fabrication of Polymer Distributed Feedback Laser by Direct Interference Ablation

The polymer distributed feedback(DFB) laser based on conjugated polymer poly(2-methoxy-5-(2′-ethylhexyloxy)-1,4-phenylene vinylene)(MEH-PPV) is reported in this paper.A one-step fabrication approach of laser ablation by two interference beams is employed and a periodic grating can be directly recorded onto the polymer layer.MEH-PPV is spin-coated to form a 400-nm-thick film on the substrate.The ablation experiments used a frequency-tripled Nd∶YAG laser(Spectra-physics Company) with 3 nm pulse width,10 ns pulse length,10 Hz repetition rate and 355 nm wavelength.The polymer film was exposed by two beams which were split from the UV laser with beam size of ~6 mm in diameter.The grating depth was fixed at around 100 nm by adjusting the laser power.The grating recorded on the polymer film with different periods was obtained by adjusting the writing angle.The DFB laser with grating period of 370 nm shows a lasing threshold of 182 μJ·cm-2·pulse-1.The peak wavelength and the full width at the half maximum are 609 nm and 4.2 nm,respectively.The peak position is tuned over 18 nm by increasing the period from 360 nm to 390 nm.