1995PASP..107..184L

We describe a new Fabry-Perot spectrometer that is optimized for the detection of extended, low surface brightness line emission from 1.4 microns to 2.4 microns. The instrument combines high throughput and high sensitivity, yet limits the background radiation falling on the detector. The instrument has a single 20"-200" beam and a resolving power lambda/delta-lambda ∼2500. The system is background shot noise limited in the K window and limited by a combination of read noise, dark current shot noise, and fluctuations in the OH airglow lines in the H window. We present sample spectra of some of the lowest surface brightness H2 line emission in the near-infrared obtained to date.