By popular demand, I've worked with Aivon to put my simple 'SFP2SMA' board (https://github.com/aewallin/SFP2SMA_2018.03) in a box, using an external Meanwell (+12V, -12V, +5V) PSU with a 5-pin DIN8 plug (model GP25A13D-R1B, Digikey 1866-1826-ND). The board can be used for simple frequency-transfer experiments together with almost any SFP-transciever. The TX SMA-connector is an input, and applies the waveform to the TX-pins of the SPF, producing modulated optical output. The dual RX SMA-connectors are driven by the SFP RX-pins, with some gain applied to produce around +10 dBm square-wave into a 50R load.
The front panel has three SFP status-LEDs: TX-fault (I've never seen this, but apparently the SFP should report if the TX-laser fails), RX LOS (loss of signal, active if you unplug the fiber), and mod_abs (module absent, active if no SFP is plugged)
After some adjustments to gains and component values the frequency-response is flat within 3 dB out to ca 400 MHz, and the ADEV looks reasonable at ca 1e-13/tau(s) (red datapoints in the plot below). These measurements were done with a CWDM SFP and a 2m single-mode loopback-fiber.
The box is a Hammond 1455L1201(120 mm x 103 mm x 31 mm), with custom front and back panels.
After a number of failed attempts (with HMC799, OPA859), here is a reasonably fast One Inch Photodetector using OPA818, a FDS015 photodiode, and 1.2 kOhm transimpedance. Bandwidth is above 400 MHz, with the dark-noise and frequency-response in reasonable agreement with TIASim predictions.
With the detector blocked there's quite a lot of electrical feed-through with just the spectrum-analyzer TG-output on (see blue data points, especially above 1 GHz). I tried to correct for this roughly, shown as the orange data points.
Slow pace today due to both tired legs and slow greenish terrain. The controls were grouped into two groups with a slightly boring 'tunnel' run between the areas. OK until #4, but not the greatest direction towards #5, and then after wading through the swamp and green area towards #10 I decided from within the control-circle to go check that the yellow swamp on the right really is there... (#10 was probably the hardest control on this map). Good weather around +18 C.