DIY Optical Power Meter with SFP (Small Form-factor Pluggable transceiver) and DDM (Digital diagnostics monitoring ) protocol

To build DIY optical power meter with standard SFP module and Arduino
- Can measure optical power in dbm and watt
- Can Enable/Disable TX power output (laser source)
- Can debug via UART

And Arduino Library
- a lib for SFP/DDM interfacing (not only optical sfp transceiver
- to interface and interpret DDM (Digital Diagnostics Monitoring ) protocol (which used in most optical fiber communication) scheme and format
- to debug, monitor, detect alarm and control SFP via DDM
- to extend the capability of handling data TX/RX interface (Arduino data over optical fiber)

Initial concept

- Most optical fiber module in today communication used from factor called SFP (small form-factor pluggable) physical interfacing. SFP is widely used in many switches, routers and many telecom devices. SFP modules comes with various transceivers option from electrical to optical interfaces such as Ethernet, Giga-bit Ethernet, optical fiber , SONET, STM, etc.

- Although transceivers are different, all SFP modules are controllable with a standard protocol named DDM (Digital Diagnostics Monitoring).

- DDM is The operating and diagnostic information is monitored and reported by a microcontroller inside the transceiver, which is accessed via a 2-wire serial bus (also known as “I2C” or “I2C” protocol).

- I2C bus interfacing is easily done by Arduino

- So, initial idea is to build an Optical Power Meter from scratch by using Arduino and Optical SFP modules + LCD + keypad

https://canli.in/splicing-machine/

http://electron9.phys.utk.edu/optics421/modules/m8/optical_fiber_measurements.htm

The fiber optic power meter is a special light meter that measures how much light is coming out of the end of the fiber optic cable. The power meter needs to be able to measure the light at the proper wavelength and over the appropriate power range. Most power meters used in datacom networks are designed to work at 850nm and 1300nn. Power levels are modest, in the range of –15 to –35dBm for multimode links, 0 to –40dBm for single mode links. Power meters generally can be adapted to a variety of connector styles such as SC, ST, FC, SMA, LC, MU, etc.

Generally, multimode fiber is tested with LEDs at both 850nm and 1300nm and single mode fiber is tested with lasers at 1310nm and 1550nm. The test source will typically be a LED for multimode fiber unless the fiber is being used for Gigabit Ethernet or other high-speed networks that use laser sources. LEDs can be used to test single mode fibers less than 5000 meters long, while a laser should be used for long single mode fibers.

Most fiber optic power meters are calibrated in linear units such as milliwatts or microwatts. They may also provide measurements in decibels referenced to one milliwatt or microwatt of optical power. Typically, fiber optic power meters include a removable adaptor for connections to other devices.