EEEL Produces Two New Wavelength Calibration Standards for the Wavelength Division Multiplexing L-Band

William Swann and Sarah Gilbert of the EEEL Optoelectronics Division have developed two wavelength calibration transfer standards for the new L-band of wavelength division multiplexed (WDM) optical fiber communication systems. These standards, based on the absorption spectrum of carbon monoxide, are now available as Standard Reference Material (SRM) 2514 and 2515.

Wavelength division multiplexing in optical fiber communication systems increases bandwidth by using many wavelength channels. Current WDM systems typically employ 50 or 100 GHz channel spacing (0.4 or 0.8 nm, respectively) in the 1530–1560 nm WDM C-band, but WDM is expanding into the L-band region (approximately 1565–1625 nm). Wavelength references are needed in these regions to calibrate instruments such as optical spectrum analyzers, tunable lasers, and wavelength meters that are used to characterize WDM system components and measure the channel wavelengths. To complement our wavelength calibration references for the WDM C-band (SRM 2517a, acetylene, and SRM 2519, hydrogen cyanide), the Optoelectronics Division has developed SRMs 2514 and 2515. SRM 2514 can be used to calibrate the wavelength scale of measurement equipment in the 1560 to 1595 nm region. The unit is a single-mode optical-fiber-coupled absorption cell containing carbon monoxide 12C16O gas, which has many absorption lines in this region. The Optoelectronics Division has characterized the pressure-induced shifts of these absorption lines and certifies the center wavelengths of 41 lines with uncertainties ranging from 0.4 to 0.7 pm. SRM 2515 is nearly identical to SRM 2514, except that it contains the 13C16O isotopic species of carbon monoxide. This isotopic species has numerous absorption lines at longer wavelengths, ranging from 1595 to 1630 nm. The Optoelectronics Division also certifies the center wavelengths of 41 lines for this SRM. Since they are based on the quantized vibrational and rotational motion of molecules, these SRMs provide wavelength references that are very stable under changing environmental conditions.

Contact:

Sarah L. Gilbert, (303) 497-3120