Original caption: "Tunable Diode Laser Chip in the Eye of a Needle

Tunable Diode Lasers (TDL) can be "tuned" like a radio to frequencies that allow them to look for specific gases. JPL's TDL can be used in the severe planetary environments, such as Mars, to look for water vapor (H2O) and carbon dioxide (CO2), helping us understand seasonal and climatic changes. TDL gas sensing technology is particularly good at detecting low levels of gases at the parts per million or even parts per billion level. Back home on Earth, the sensors have applications for environmental monitoring, atmospheric science, medicine and communications. Tunable Diode Lasers offers greater speed, robustness, sensitivity and range compared to traditional sensors, all for a size that can fit in the eye of a needle." [1] This is the chip contained within the package seen here:[2]

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