Synthesis of optical standard frequencies in the S, C and L telecommunication bands by use of four-wave mixing in semiconductor optical amplifiers

Abstract

The generation of standard reference frequencies close to the ITU channels is essential for the calibration and maintenance of DWDM systems. This work describes a method to synthesize frequency references in the range from 187.1 to 205.1 THz (1462-1602 nm). The method is based on the generation of four equispaced frequencies (by the process of four-wave mixing in a semiconductor amplifier) of which two are locked to absorption lines of the acetylene 12C2H2 (1511-1542 nm).Ministerio de Educación y Cienci

Double spacing multi-wavelength L-band Brillouin erbium fiber laser with Raman pump

“…The 11 channels with signal power above À33 dBm with average OSNR of 20 dB were counted important. This to assure that this laser is compatible with some existing DWDM systems [18][19][20]. The anti-Stokes generation is mainly due to the FWM effect.…”

Generation of a reference frequency comb by cascaded four-wave mixing enhanced by Raman amplification

“…One is used for stabilization of the two initial frequencies at the selected frequencies by means of the acetylene cell, and the other are coupled together and used for the frequency comb generation. To lock both lasers (TL1 and TL2) to the absorption lines of the acetylene cell used in our setup, we use a small frequency modulation, as in [7]. The peak to peak modulation of the laser frequency is 30 MHz.…”

“…In order to avoid possible interferences between the signals detected by the lock-in amplifiers, the laser beams were introduced in the absorption cell in opposite directions through two isolators, as shown in Figure 1 [7].…”

“…This approach is expensive since it requires several reference cells with accurate traceability. A couple of solutions to this problem have been demonstrated, by generating frequency references based on standard absorption lines using four-wave mixing in optical fiber [6] and in semiconductor optical amplifier [7].…”