Send Sensor value with optical fiber and arduino

Hi everybody , i want send sensor to arduino with 2km distance,
one side is a arduino to process data value and other side is an arduino to send sensor value to other arduino
help me to find out way to connect to arduino over optical fiber

Which of these solutions did you try already? And why doesn't it work for you?

Well I have never tried optical fiber communications with arduino but there are kits and shields out there for arduino.

This is 1 side of the communication: Optical Fiber Module (M122v2 TOSLINK) Fiber Optics Fibre Optics arduino | eBay

shield: Fiber Optical UART Shield for Arduino Leonardo (M120v1) Fibre Fiber Optics | eBay

Apparently this one is a complete kit which contains shield, transceievers and cable too Optical Fiber Starter Kit Fibre Optics arduino | eBay

The Actual Fiber optic cable: TOSLINK Optical Fiber arduino | eBay

From the looks of it, they convert UART signals to fiber optic signals and vice versa.