Research in the Quantum Optics Group at St. Andrews Back

Quantum optics with optical fibers:

Quantum mechanics is arguably the most successful theory of the 20th century. Especially in the last 25 years, experimental techniques matured to make possible the observation of distinct quantum mechanical effects. Among the most prominent are the nonlocality proof using Bell’s inequalities, generation of squeezed states of light, quantum-nondemolition mesaurements, creation of various types of entangled states, teleportation and quantum cryptography.

Many of these effects have been demonstrated with the use of optical fibers. The fiber is both a natural transport medium of quantum states/ quantum information, and a nonlinear medium to create many interesting quantum states. Due to the high technological level in optical communications, the experimenter is equipped with very high quality optical products at reasonable costs. The research is along the borderline between nowadays optical communications which today avoids quantum effects, and future communications utilizing quantum mechanics.

Research projects are centered around the creation of narrowband fiber-optical single photon sources for resonant coupling to atomic quantum memories, quantum optics with fiber solitons, quantum information with continuous variables and experiments in nonlocality or entanglement purification for many-photon states.

• The optical fiber – a sketch with dimensions. After 15km, still half of the light is transmitted!

• Soliton collision in the spectrum. The pulses repel each other.

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