Line centers, pressure shift, and pressure broadening of 1530-1560 nm hydrogen cyanide wavelength calibration lines

Abstract

We have measured the line centers and pressure-induced shift and broadening of 25 lines in the 2nu3 rotational-vibrational band of hydrogen cyanide H13C14N. These lines can be used as wavelength references in the optical fiber communication wavelength division multiplexing C-band (approximately 1530-1565 nm). We find that the pressure shift varies with line number from +0.09 pm/kPa to -0.15 pm/kPa (approximately -1.5 to +2.5 MHz/Torr). The pressure broadening also varies with line number and is typically between 1 and 5.4 pm/kPa (17-90 MHz/Torr). We determined the line centers of 21 lines with an expanded uncertainty (2sigma) of 0.01 pm (approximately 1 MHz), an improvement of more than 1 order of magnitude over previous line center measurements of this band. We also calculate the molecular constants for the band, yielding improved determination of the band origin frequency and the excited-state molecular constants.