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Part of: A Science Kit for Quantum Physics.

  • Single Photon Michelson Interferometer Add-On for the quED.

  • Overview
  • Sample Experiments
  • Add-Ons
  • System Includes
  • Variants
  • Downloads


Interference is generally considered to be a wave phenomenon. Curiously it also works with single quantum objects. Use the quED and the quED-MI Michelson Interferometer add-on together with the quED to show that this is the case.

There are two versions of the quED-MI, the manual and the motorized version (photo shows the latter).

Sample Experiments

Here is a list of the experiments where the quED-MI is involved.

Single Photon Experiments with Interference
Wave Nature of Photons: Single Photon Michelson Interferometer
Quantum Eraser
Wave-Particle Dualism: Michelson + HBT
Photon Pair Experiments without Polarisation Entanglement
Franson Interference

These are the experiments we have come up with so far and found interesting enough to put them here. Do you have more ideas? Please let us know!

Other Add-Ons

The functionality of the quED system can easily be extended with these add-ons:

+ quED-HBT Hanbury Brown Twiss Add-On
Perform the “Grangier Experiment”, explore the particle nature of single photons with a Hanbury Brown & Twiss setup and build a quantum random bit generator.

Hanbury Brown & Twiss Setup for Heralded Single Photon Sources.

  • Hanbury Brown-Twiss setup Add-On for the quED

Photons (or generally quantum objects) sometimes also behave like particles. With this add-on you can show that photons can not be split up. You can also explore a simple quantum random bit/number generator and use it in combination with the quED-MI to show wave and particle nature of photons in one experiment.

Read more about the quED-HBT.

+ quED-HOM Hong–Ou–Mandel Effect
Experience the purely quantum 2-photon interference effect by revealing the Hong-Ou-Mandel dip.

Hong-Ou-Mandel Interferometer Demonstrating 2-Photon Interference.

  • Hong-Ou-Mandel effect Add-On for the quED

When you have two indistinguishable photons and each of them hit one input of a beam splitter, they exit the beam splitter together in one output port. This is an effect you cannot demonstrate with bright light, but with this add-on you can.

Read more about the quED-HOM.

+ quED-QKD Quantum Cryptography

Securely distribute a secret key between Alice and Bob with the BB84 protocol.

Quantum Cryptography Add-On for the quED.

One of the most popular industrial applications for quantum phenomena right now is quantum cryptography, or better, quantum key distribution. With this add-on, you can use weak coherent pulses to simulate realistically how a secure communication between two parties (Alice and Bob) is made possible by the BB84 protocol in a real environment.

Read more about the quED-QKD.

+ quED-TOM Quantum State Tomography Add-On
The quED-TOM let you determine the full quantum state density matrix that defines all properties of either a single photonic qubit or even the two-qubit entangled or non-entangled state that can be produced in the quED source.

Quantum State Tomography Setup

  • Setup of the manual 2-photon tomography with the quED.

A quantum mechanical state can not be determined using only a single measurement. But, if you have an ensemble of equally prepared states, as, e.g., by our SPDC source, there is a procedure that makes the complete determination of the quantum state, i.e. its density matrix, possible.

Read more about the quED-TOM.

System Includes

The quED-MI is an add-on to the quED and consists of the following parts:

  • Michelson interferometer with polarization maintaining fibre input and single mode fibre output
  • 3 Polarizers that can be swung in and out of the interferometer.


There are two variants of the quED-MI:

  • Manual: Ideal for student lab courses, where the students are supposed to perform the measurements themselves.
  • Motorized: Intended for demonstrations during lectures or at science exhibitions, classes and research, when the result matters more than the process of measuring. Here, the linear translation stage is replaced by a motorized one.


quED-MI manual 01/2019 2.2 MB pdf
quED-MI sample solution 01/2019 1.8 MB pdf