Tahir Jamal Muhammad, Hansen Anders Kragh, Tawfieq Mahmoud, Andersen Peter Eskil, Jensen Ole Bjarlin
Opt Express. 2020 Oct 12;28(21):31754-31762. doi: 10.1364/OE.404968.
One of the major factors that limits the widespread use of ultrafast titanium sapphire (Ti:S) lasers in life science is its expensive and complex pump source. Broad area diode laser (BA-DL) based pump sources have high potential to solve this problem, since they are compact, inexpensive and very efficient. However, their non-diffraction limited beam profile makes it challenging to achieve high powers in Kerr-lens mode-locked (KLM) operation of Ti:S lasers. In this work, we show that the ideal way to beam shape two spectrally combined BA-DLs with different beam qualities is to aim for a compromise between matching to the cavity mode diameter and the cavity mode Rayleigh range. We furthermore conclude that the relative intensity noise (RIN) of the BA-DL pumped Ti:S laser, another important parameter for imaging applications, is sufficiently low for a wide range of life science applications. However, for applications that are highly sensitive to noise, new laser diode designs are likely necessary to reduce inherent noise originating within the laser diode.
限制超快钛宝石（Ti:S）激光器在生命科学领域广泛应用的主要因素之一是其昂贵且复杂的泵浦源。基于宽面二极管激光器（BA-DL）的泵浦源有很大潜力解决这一问题，因为它们体积紧凑、价格低廉且效率很高。然而，其非衍射极限光束轮廓使得在Ti:S激光器的克尔透镜锁模（KLM）操作中实现高功率具有挑战性。在这项工作中，我们表明，对具有不同光束质量的两个光谱组合BA-DL进行光束整形的理想方法是在匹配腔模直径和腔模瑞利范围之间寻求折衷。我们还得出结论，BA-DL泵浦的Ti:S激光器的相对强度噪声（RIN）是成像应用的另一个重要参数，对于广泛的生命科学应用来说足够低。然而，对于对噪声高度敏感的应用，可能需要新的激光二极管设计来降低激光二极管内部产生的固有噪声。
