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GFF by Chirped FBG features:
Accurate gain profile
     matching
Reliable thermal stability
Fast prototyping
Economic production
     flexibility

GFF by Long Period Gratings features:
Flexible bandwidth
     coverage
Better cost/performance
     value
Fast prototyping
Economic production
     flexibility

Main Applications:
EDFA for DWDM system
ASE Source
Raman Amplifier
  Description:
The gain flattening filter (GFF), or gain equalizer (GEQ), is used to compensate for the uneven gain amplification at different DWDM channel by Er-doped fiber amplifier (EDFA). Broptics develops two fiber grating technologies to achieve best price/performance value for customers.

Chirped Fiber Bragg Gratings (CFBG)
Chirped gratings is a sequence of grating periodic change along the transmission axis. By modifying the intensity of grating depth, a matched gain compensation profile can be created. CFBG is able to match the desired profile with minimum errors. Also, Broptics patent-pending athermal package can be applied to resist temperature drift. CFBG is the right choice for high performance EDFA design.

Long Period Gratings (LPG)
Long period gratings differentiate from normal FBG by much wider grating period. The matched wavelength is coupled to cladding mode and absorbed or attenuated. By designing a series of different long gratings, a matched gain compensation profile can be created. Due to its wider period, LPG can be easier made to cover wider bandwidth. By properly select specialty fiber, LPG can be used when cost is the major concern.
Specification Spectral Response
Type LPG
Chirped FBG
Wavelength range
Error function
Thermal stability
Max attenuation
Return loss
Wide bandwidth
+/- 0.5dB
< 10pm/óJ
<15dB
Low
S & C
+/- 0.25dB
< 1pm/óJ
<10dB
High
 
 
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