I know the question is quite stupid since basic MOPA need isolator to prevent backward reflection and reduced noise. But there are no isolator in our lab thus we just operate MOPA setup without cladding mode stripper (CMS) and isolator. The amplifier setup is bidirectional pump.
To operate the MOPA seed laser is set to 5W and the pump power at the amplifier increase. When the pump power is low the output power of the whole MOPA setup is increase. But suddenly at one point a sudden drop occur (5W to 1W) and the ouput power insignifacntly increase by increasing pump power. When the power drop high output power was recorded at the end of FBG at the signal port. Based on previous experience at the end of high reflector (HR) FBG, its power should be low (mW in my previous case) but for this setup it output recorded around 2W.
there are 2 possibilities for this issue either the HR FBG is not good enough or due to the MOPA setup that no equoped with CMS and isolator
You can see the following links:
1. https://opg.optica.org/abstract.cfm?uri=oe-17-26-24008
2. https://opg.optica.org/oe/fulltext.cfm?uri=oe-30-9-15575&id=471632
3. https://hal.archives-ouvertes.fr/hal-01551394/document
4. Article High-power single-frequency pulsed fiber MOPA via SPM suppre...
- Badges
- Science topic
- Similar topics
- Phytochemistry
- Extracts