Lens Fabrication Method Clears Way for Portable Gas Sensor's Preferred Light Source

The Toulouse researchers favored a near-infrared single-mode laser diode source — a VCSEL — for their microsystem; these semiconductor lasers benefit from their compact size and can be spectrally tuned over a few nanometers simply by adjusting the operating current. The VCSEL chip used in their work also includes a grating relief etched at its surface. This ensures strong polarization stability of the emitted beam.