Practical and High-Energy Near- to Mid-Infrared Femtosecond Oscillators for Directly Writing Silicon Waveguides in Three Dimensions

自10年前第一次演示以来，使用飞秒激光直接写入光波导一直是许多研究的主题。尽管光写入半导体波导具有巨大的潜力，但在这一领域仍然几乎普遍缺乏研究。对此最有可能的解释是一个实用的解释；只有钛蓝宝石放大器通常可以提供足够的脉冲能量来创建波导，但它们的800 nm波长不是由硅等半导体传输的，因此不可能创建亚表面波导。为了解决这个问题，我们提出了一种新的基于腔倾倒和扩展腔操作相结合的飞秒光学参量振荡器的能量定标方法。通过这种方式，我们希望产生能量在1uJ左右的近红外和中红外脉冲，这应该足以在各种材料中写入波导，我们打算通过集中在硅片中创建波导来验证这一点。该项目结合了超快光学集团在飞秒激光加工、亚表面硅显微镜和飞秒参数源开发方面的广泛专业知识。

Direct-writing of optical waveguides using femtosecond lasers has been the subject of much research since the first demonstration 10 years ago. Despite the great potential of optically-written semiconductor waveguides, there remains an almost universal absence of research in this area. The most likely explanation for this is a practical one; only Ti:sapphire amplifiers can typically provide sufficient pulse energy for waveguide creation but their 800nm wavelength is not transmitted by semiconductors such as silicon, so the creation of sub-surface waveguides is impossible. We propose to address this problem by developing a new energy-scaling approach to femtosecond optical parametric oscillators based on combining cavity-dumping with extended-cavity operation. In this way we expect to produce near- and mid-infrared pulses with energies around 1uJ which should be sufficient to write waveguides in various materials, and we intend to verify this by concentrating on waveguide creation in silicon wafers. The project combines broad expertise in the Ultrafast Optics Group in femtosecond laser machining , sub-surface silicon microscopy and femtosecond parametric source development .