Calibrated Fabry-Perot etalon as 1.5-μm wavelength region absolute frequency reference based on double acetylene absorption lines

Abstract

ABSTRACT Absolute frequency reference in 1.5-­ m wavelength region is very useful for DWDM system. We have studied on producing artificial 1.5-­ m wavelength region absolute frequency reference by calibrating the F-P etalon. Double acetylene absorption line calibrating techniqu e was adopted. An experiment of calib rating the Fabry-Perot etalon using double acetylene absorption lines has been demonstrated. In the experiment, Mode 1996 of the F-P et alon was locked to acetylene absorption line 1533 .4621 nm. The frequency stability of the calibrated F-P etalon was about 7h 10 -8 . After calibrating, a series of artificial ab solute frequency references in 1.5- ­ m wavelength region was obtained. To reduce the complexity of calibrating, a novel frequency difference measurement me thod was introduced. Keywords: frequency stabilization, frequency standard, frequency reference, Fabry-Perot, fiber bragg grating external cavity laser diode, acetylene absorption 1. INTRODUCTION With the development and progress of Dense Wavelength Division Multiplexing (DWDM), the interval between optical communication channels becomes narrower and narrower, so equipments in DWDM system are required to have more stability and accuracy. The ITU Telecommunication Standardization Sector (ITU-T) produced standards for optical telecommunications and recommended a series of equal spaced frequency points in 1.5-­ m wavelength region as communication channels. It is in urgent need of absolute frequency reference that satisfies ITU-T standards in 1.5-µm wavelength region for frequency calibration. Acetylene absorption lines with high accuracy and stability can be used as 1.53-µm wavelength region absolute frequency reference