Description: Our phase I effort validated the ability of a properly designed micro-electromechanical systems vertical cavity surface-emitting laser (MEMS-VCSEL) to sense fiber bragg gratings at a distance of several meters, using reasonable Analog to Digital (A-D) converter rates of a few hundred MHz. In addition, we demonstrated that our electrically pumped MEMS-eVCSELs can be packaged with an amplifier in a single 14-pin butterfly package, which remains robust through vibration testing at peak accelerations exceeding 10g, using a standard MIL-SPEC vibration spectrum. These results form the foundation for our phase II effort, in which we will re-design the laser cavity to further reduce noise and enable fiber bragg grating sensing at >10meters. This work will progress through 5 objectives. In objective 1, we will develop a low-noise optically pumped device designed for >10meter sensing. Our subcontractor Sensuron will validate this device and develop detection electronics in objective 2. Objective 3 will duplicate objective 1 performance in a ruggedized electrically pumped version, which our subcontractor will integrate into a ruggedized sensing system under objective 4. In objective 5 we will develop an ultra-low noise MEMS-VCSEL source capable of sensing tens of meters.

Benefits: This work will develop a new cost-effective ruggedized laser technology that will accelerate proliferation of optical frequency domain reflectometry (OFDR) fiber optic sensing of physical parameters such as shape, deflection, temperature, and strain. This will impact the structural engineering and testing of cutting-edge structures and vehicles for land, air, water, and space. This laser technology can also be embedded into vehicles for continuous in-flight structural and health monitoring.

This work will create a new rugged 1550nm widely tunable laser source which provides continuous single mode tuning with low size, weight, and power dissipation in an economical package. This source has non-NASA applications in structural monitoring of military and commercial aircraft, of wind turbines, and in metrology, spectroscopy, and medical shape sensing.