SAM – saturable absorber mirror

The main applications for SANOS are:●●●noise suppression in free space optics, for example after a pulse pickerreshaping of fibre guided optical signalsopto-optical wavelength conversion.For these two applications the following devices has been developed:●●Free space SANOS (FS-SANOS)Fibre coupled SANOS (FC-SANOS)> Free space SANOS (FS-SANOS)The free space SANOS is devoted to clean a pulsed opticalbeam from noise. One possible application is after a pulsepicker to suppress the residual pulses, which has been passedthe picker with a low intensity. An other application is tosuppress the amplified spontaneous emission (ASE) of anoptical amplifier.The optical beam is twofold reflected inside the FS-SANOS.The first mirror is a nonlinear RSAM. The second mirror iseither a common linear high reflectance mirror or a RSAM.The transmittance T of the FS-SANOS depends on the peak power density I of the input beam accordingto the nonlinear reflectance of the RSAM. The output beam intensity I out is related to the input beamintensity I bywithT(I)I out = T(I) Iintensity dependent transmittance.A typical transmittance curve of a FS-SANOS with one RSAM inside shows the figure above.> Fibre coupled SANOS (FC-SANOS)The fibre coupled SANOS can be used for noise suppression inoptical fibre channels. To reshape an optical signal the passiveFC-SANOS can be simply insert into a fibre channel after anEDFA. Due to the working principle of the SANOS this devicereshapes only the amplitude of one wavelength.The active device inside the FC-SANOS is a RSAM, mounted ona circulator.> Effective saturation fluence Φ sat,effSeongKyeong Photonics 23 info@skphotonics.com