| 摘要 |
The system and method operates to calibrate a transmission laser of the dense wavelength division multiplexer (DWDM). In one example, the transmission laser is a widely tunable laser (WTL) to be tuned to one of a set of International Telecommunications Union ITU) transmission grid lines for transmission through an optic fiber. The WTL is tuned to the ITU grid using an etalon and a gas cell having acetylene, hydrogen cyanide or carbon dioxide. Initially, the absolute transmission wavelengths of the WTL are calibrated by routing an output beam from the WTL through the etalon and through the gas cell while varying tuning parameters of the WTL to thereby generate an etalon spectrum and a gas absorption spectrum both as functions of the tuning parameters. The etalon and gas absorption spectra are compared, along with input reference information specifying gas absorption spectra are compared, along with intput reference information specifying gas absorption as a function of absolute wavelength, to determine the absolute transmission wavelength for the WTL as a function of the tuning parameters. The WTL is then tuned to align the transmission wavelength of the WTL to an ITU transmission grid line. By tuning the output wavelength of the WTL using an etalon in combination with a gas absorption cell, the WTL can be quickly, easily and precisely set to a selected ITU transmission grid line at the point of installation. The tuning process can be periodically repeated to maintain precise tuning of the WIL despite possible temperature or mechanical drift of the various components. In one implementation, a hand-held wavelength mapper is provided for manually connecting to a WTL to a selected ITU transmission gridline. In another implementation, the wavelength mapper is permanently attached to the WTL along with wavelength locking components to lock the WTL to an ITU transmission gridline. In another example, a technique is described for calibrating a laser with multiple tuning parameters using a pair of etalon of differing thickness. Also disclosed is a locket for use with lasers with multiple tuning parameters. |
