According to the data sheet for the third party SFP I am using the optical receive range is from 1200 to 1600nm. While the minimum receive is -13.2dBm for the SFP, the SFP does appear to be capable of measuring accurately down to -28dBm.
My light source is an Anristu light source 1310 and 1550nm and according to the datasheet has a launch power of -7dBm for both 1310nm and 1550nm. With no attenuation added I was measuring -5.9 at 1550nm and -5.5 at 1310nm.
While SFF-8472 states that the optical power receive accuracy must be better than +/-3dB clearly my third party SFP was remarkable accurate when compared to my nice expensive calibrated power meter.
| Added Attenuation | 1550 | Meter | sfpduino | 1310 | Meter | sfpduino |
| 0dB | -5.90dBm | -5.81dBm | -5.50dBm | -5.50dBm | ||
| 5dB | -10.50dBm | -10.11dBm | -10.10dBm | -10.12dBm | ||
| 8dB | -13.50dBm | -13.51dBm | -13.90dBm | -13.59dBm | ||
| 11dB | -17.10dBm | -17.21dBm | -17.90dBm | -17.93dBm | ||
| 14dB | -19.40dBm | -19.59dBm | -18.9dBm | -19.43dBm | ||
| 15dB | -20.20dBm | -20.36dBm | -19.70dBm | -20.04dBm | ||
| 18dB | -22.90dBm | -23.77dBm | -22.50dBm | -23.77dBm | ||
| 21dB | -23.8dBm | -24.20dBm | -23.60dBm | -24.56dBm | ||
| 25dB | -25.60dBm | -26.99dBm | -26.00dBm | -28.86dBm | ||
| 30dB | -31.10dBm | -40dBm | -33.00dBm | -40.00dBm |
Thanks for sharing this essential information about optical power meter. Your post is important to us.
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