SBIR Phase I: Single-Mode Single-Polarization VCSELs at any Wavelength

这个小企业创新研究第一阶段项目建议使用一种新的方法来制造垂直腔面发射激光器（VCSELs），该激光器不受其主机半导体衬底施加的任何波长限制。这些革命性的vcsel将在单模下工作，具有高输出功率，窄线宽和稳定的线偏振，用于光谱学和通信。在这种方法中，VCSEL的两个半导体分布式布拉格反射器（dbr）大部分被消除。在一侧，高对比度亚波长光栅（HCG）反射镜用于单模线偏振输出。在另一边，用介电DBR代替高反射器。利用这种组合，可以在覆盖近红外和接近中红外（800nm至2500nm）的任何波长上构建高效的单模vcsel。通过极低的电阻和高效的散热，实现高效率和高输出功率。第一个原型机的发射波长将达到1550nm，其雄心勃勃的目标是在长距离光纤通信和近红外光谱中提供DFB激光器的首选替代品。第一阶段将完成HCG制造和完整的设计，随后进行外延生长。该项目的更广泛影响/商业潜力范围从电信到光谱。所开发的器件将具有DFB激光器的模式纯度和线宽，以及VCSEL在任何近红外波长下的光束质量和低成本，并具有稳定的线偏振输出。直接应用领域是电信和光谱学。在通信系统中，降低每比特的成本和每比特传输数据的功耗是特别有趣的。与现有的基于边缘发射器的解决方案相比，在光纤收发器单元中实施所提出的vcsel可以降低成本和功耗。降低功耗进而导致小型化和高密度组装，从而进一步降低成本。到目前为止，长波长1550nm的vcsel还没有具备广泛应用所需的特性。vcsel要满足的特别具有挑战性的要求是高光输出功率和长距离传输的窄线宽。所提出的方法使这些vcsel能够满足所有要求，并有可能成为边缘发射DFB激光器的有吸引力的替代品。由于缺乏波长限制，这些光源非常适合用于环境和安全应用的近红外泛音光谱。

This Small Business Innovation Research Phase I project proposes to use a novel approach to fabricate Vertical Cavity Surface Emitting Lasers (VCSELs) that are free from any wavelength limitations imposed by their host semiconductor substrate. These revolutionary VCSELs will operate in a single mode with high output power, narrow linewidth and stable linear polarization for use in spectroscopy and communications. In this approach, both semiconductor distributed bragg reflectors (DBRs) of the VCSEL are mostly eliminated. On one side, a high-contrast subwavelength grating (HCG) mirror is used for single-mode linearly polarized output. On the other side, the high reflector is replaced with a dielectric DBR. Using this combination, it is possible to build efficient single mode VCSELs at any wavelength covering near-infrared and approaching mid infrared (800nm to 2,500nm). High efficiency and high output power are achieved by very low electrical resistance and efficient heat sinking. The first prototype will have an emission wavelength of 1550nm with the ambitious goal of offering a preferred alternative to DFB lasers in long-haul fiber optic communications and near infrared spectroscopy. HCG fabrication and a complete design followed by epitaxial growth will be done in Phase I.The Broader Impacts / Commercial Potential of this project range from telecommunications to spectroscory. The developed devices will have the mode purity and linewidth of DFB lasers and the beam quality and low cost of a VCSEL at any near infrared wavelength with stable linearly polarized output. Immediate application areas are in telecommunications and spectroscopy. Of particular interest in communication systems are the reduction of cost per bit, and power consumption per bit of transmitted data. Implementing the proposed VCSELs in fiber optic transceiver units results in reduced cost and reduced power consumption over existing edge emitter based solutions. Reducing power consumption in turn leads to miniaturization and high density assembly that lead to further cost reduction. Up to now, long wavelength 1550nm VCSELs have not had the required characteristics to gain widespread use. Particularly challenging requirements for VCSELs to meet are high optical output power and narrow linewidth for long haul transmission. The proposed approach makes possible for these VCSELs to meet all the requirements and to potentially become an attractive alternative to edge emitting DFB lasers. The lack of wavelength constraints makes these sources ideal for overtone spectroscopy in the near infrared for environmental and security applications.