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Optics have thresholds for how strong or weak of a light level they can receive before they'll theoretically fail
The purpose of this page is to help estimate if a particular optic will work on a particular fiber span
Other factors, such as optical signal-to-noise ratio, reflections, and dispersion, are important and impact your optical performance but are not discussed here

Terminology

Power level
- The power level from optics is measured in microwatts but converted to dBm for ease of reading by humans
- dB is on a logarithmic scale
- The higher the dBm the stronger your receive level
- The lower the dBm the weaker your receive level

Milliwatts to dBm conversion table and some examples (rounding happening on some examples)
- Note! Not shown: LR, ER, and ZR max receive levels are not shown here.

Power in milliwatts	Power in dBm	1310 and 1550 10G Optic Examples
10	10
	9
	8
	7
4	6
	5
	4
2	3
	2
	1	Transmit minimum for some 10G ZR optics (80km)
1	0
	-1	Transmit minimum for some 10G ER optics (40km)
	-2
	-3
	-4
	-5
	-6
	-7
	-8	Transmit minimum for some 10G LR optics (10km)
	-9
0.1	-10		LR	ER	ZR
	-11		~6dB power budget	~11dB power budget	~23dB power budget
	-12
	-13
	-14	Receive minimum for some 10G LR optics (10km)
	-15	Receive minimum for some 10G ER optics (40km)
	-16
	-17
	-18
	-19
0.01	-20
	-21
	-22
	-23	Receive minimum for some 10G ZR optics (80km)
	-24
	-25
	-26
	-27
	-28
	-29
0.001	-30

Ballpark estimates:
- 0.25dB loss per kilometer for 1550nm
- 0.5 dB loss per kilometer for 1310nm
- 0.3 dB loss per connector

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