Systems for spectroscopy are provided. Exemplary systems include: an enclosure; a tunable laser disposed in the enclosure; an opening on a surface of the enclosure; a beam splitter disposed in the enclosure, the beam splitter being optically coupled to the tunable laser and the opening; a sensor, a sensing surface of the sensor having a filter disposed thereon; and electronics coupled to the tunable laser and the sensor, the electronics including a processor, memory, and a battery.