The HR4000 high-resolution miniature fiber optic spectrometer from Ocean Optics Inc. has a 3648-element CCD array detector that provides optical resolution of 0.02 nm FWHM, and spectral response is between 200 and 1100 nm. Both resolution and wavelength range vary, depending upon which of 13 diffraction gratings and which entrance slit width the user chooses. Options for the latter are 5, 10, 25, 50, 100 or 200 µm. Dynamic range is 2.5 × 109, and signal-to-noise ratio is 2500:1 for a single integration period. The spectrometer connects to a PC via a USB-2.0 or an RS-232 interface. The USB interface enables full spectral scans into memory every 4 ms. Applications include wavelength characterization of lasers, and determination of gas absorbance and of elemental atomic emission lines.