Research work must be able to provide or develop useful and necessary technologies for U.S. space missions. Although JPL also encourages researchers to publish papers, it pays more attention to whether the research results can be used for it. My work there is to develop advanced mid-infrared semiconductor laser pointer whose performance indicators must meet the requirements of internal and external customers for the detection of designated molecules.
This is different from general basic research standards, and the issues involved span semiconductor physics, material growth, quantum device design, fabrication, packaging, reliability, and so on. The challenges are multifaceted, and it is also a rare opportunity and honor for our research work to contribute to human interstellar exploration.
In the first few years, our team has developed some single-mode tunable interband cascade lasers in important bands for trial use by relevant customers, and received their affirmation and feedback. Then we got the opportunity to provide inter-band cascade lasers for Mars expedition missions. This laser is designed to detect methane gas on Mars. It has very strict requirements on its technical indicators such as power consumption, working temperature, output power, lasing wavelength, and adjustable range. In the limited time at that time, it was almost impossible. Possible.
But there was no better choice than our laser. Therefore, this laser is listed as the most risky project. This means that if our progress does not reach a series of pre-set milestones, the project may be replaced by a backup plan at any time. Although the pressure is huge, the momentum is unstoppable.
The preliminary work gave our team a clear understanding and preparation, in which physical considerations played a key role. The related technical details have been published, so I won’t repeat them in this article. We delivered inter-band cascade green laser pointer that met the requirements in early 2007. One of them landed on Mars with the Curiosity Mars rover in 2012 and successfully detected methane on Mars.