Calculate Power & Energy Loss in Optical Fibre: 0.8dB/km @ 1250nm

Click For Summary

Discussion Overview

The discussion revolves around calculating power loss and energy loss in an optical fiber with a specified loss rate of 0.8 dB/km at a wavelength of 1250 nm. Participants are addressing both the immediate calculation of power loss over a distance of 20 km and the energy loss over a 24-hour period.

Discussion Character

  • Homework-related, Technical explanation

Main Points Raised

  • One participant asks for help with calculating the power loss and energy loss in the optical fiber.
  • Another participant questions the meaning of 0.8 dB and suggests reviewing a resource for clarification.
  • A third participant encourages the original poster to explore how decibels relate to power, implying that understanding this relationship is crucial for solving the problem.
  • A later reply offers an additional reference to help clarify the dB to power relationship, suggesting that the initial reference may be confusing for beginners.

Areas of Agreement / Disagreement

There is no consensus on the calculations, as participants are providing guidance and resources rather than definitive answers. The discussion remains unresolved regarding the specific calculations requested.

Contextual Notes

Participants have not provided specific assumptions or mathematical steps necessary for the calculations, which may affect the clarity of the discussion.

aero_mech13
Messages
1
Reaction score
0
Hi guys,

can anyone help me with this question?-

An optical fiber has a loss of 0.8dB/km at a wavelength of 1250nm. If 120uW of power is injected into the fibre at the transmitter, how much power would be lost at a distance of 20km down the fibre, also calculate the energy loss over a 24hr period?

Regards
 
Physics news on Phys.org
What's the meaning of 0.8 db? If you're not sure, review here: http://hyperphysics.phy-astr.gsu.edu/hbase/sound/db.html"
 
Last edited by a moderator:
Welcome to the forums,

Have you made any attempt at this question yourself? My first suggestion would be to figure out how dB relates to power...

Edit: This is getting to be a regular occurrence Doc :redface:
 
Doc Al is putting you on the right track. But his dB reference may be confusing to someone just learning about power relationships. Here's another reference to shed more light. You will see some examples relating power.
 

Similar threads

Power margin of a fiber-optic system
  • · Replies 5 ·
Replies
5
Views
2K
Graduate Calculate the energy-loss straggling of particles using LISE++
  • · Replies 1 ·
Replies
1
Views
4K
Attenuation Coefficient in an optical fibre
  • · Replies 21 ·
Replies
21
Views
2K
AC power loss in lossy dielectric (capacitor) with DC-bias field
  • · Replies 4 ·
Replies
4
Views
2K
Estimating loss-limited transmission distance
  • · Replies 6 ·
Replies
6
Views
3K
Loss of energy in DC and loss reduction in AC circuits
  • · Replies 2 ·
Replies
2
Views
2K
Extreme Fiber Coupled Laser Diode Power Loss
  • · Replies 6 ·
Replies
6
Views
2K
Long distance electrical transmission efficiency
  • · Replies 2 ·
Replies
2
Views
2K
Undergrad Potential energy loss related to force applied?
  • · Replies 5 ·
Replies
5
Views
2K
Calculate the power measured by the detector at distance h from the source
  • · Replies 34 ·
2
Replies
34
Views
4K