How to Measure Entangled Photons in the 45/135 Basis with Wave Plates and PBS?

Click For Summary
SUMMARY

This discussion focuses on measuring entangled photons in the 45/135 basis using 22.5-degree wave plates and polarizing beam splitters (PBS) oriented in the horizontal/vertical (H/V) basis. The entangled states are represented as |H>|V> - |V>|H> and can be transformed using wave plates to achieve |45>|135> - |135>|45>. The PBS allows for the determination of whether a photon has passed the 45-degree or 135-degree polarization test based on the output states |H> or |V>. The challenge arises when measuring four entangled photons, as the output states can be ambiguous without additional context.

PREREQUISITES
  • Understanding of quantum entanglement and photon polarization
  • Familiarity with wave plates and their role in polarization manipulation
  • Knowledge of polarizing beam splitters (PBS) and their function in quantum optics
  • Basic concepts of quantum state representation and measurement
NEXT STEPS
  • Research the principles of quantum entanglement in multi-photon systems
  • Study the operation and applications of 22.5-degree wave plates in quantum optics
  • Explore the mathematical representation of quantum states and measurement outcomes
  • Investigate advanced techniques for distinguishing between polarization states in entangled photon experiments
USEFUL FOR

Quantum physicists, optical engineers, and researchers working in quantum optics or photonics who are interested in the measurement of entangled photon states and polarization techniques.

StevieTNZ
Messages
1,944
Reaction score
837
In regards to measuring two photons in the 45/135 basis using 22.5 wave plates and PBS orientated in the H/V basis:

Is it with the entanglement |H>|V> - |V>|H>, with the wave plates:
H -> 45
V -> 135
so
|45>|135> - |135>|45>
And back again using a PBS:
|H>|V> - |V>|H>

So getting |H> at the PBS indicates that the photon passed a '45 degree test'? Likewise with |V> indicating the photon was tested in the |135> polarisation, and it 'passed'?

When we measure in the 45/135 basis with four photons entangled as |H>|V>|V>|H>-|V>|H>|H>|V>, how do we tell with the PBS whether we subjected each photon to a test in 45 or 135 basis, when |H>|V>|V>|H> could be |135>|45>|135>|45> or |45>|135>|45>|45>?
 
Physics news on Phys.org

Similar threads

  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 41 ·
2
Replies
41
Views
7K
  • · Replies 3 ·
Replies
3
Views
1K
  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 1 ·
Replies
1
Views
2K
Replies
6
Views
4K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 13 ·
Replies
13
Views
5K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K