A near infrared (NIR) semiconductor laser system is shown for gas sensing. An embodiment is centered on the use of a system with a much wider tunable laser, which today has a scan band of more than 150 nanometers (nm) to as much as 250 nm or more. In some cases the scan band is about 400 nm or more. This is achieved in the current embodiment through the use of a widely tunable microelectromechanical system (MEMS) based Fabry-Perot filter as an integral part of the laser cavity. Using this technology, these systems are capable of capturing a variety of gases in the any of the well-known spectroscopic scan bands, such as the OH, NH or CH. For example, a single laser with a 250 nm scan band window between 1550-1800 nm can capture ten or as many as twenty hydrocarbon-based gases simultaneously.