Martin van Exter Lab - Quantum Optics and Light-Matter Interaction
Prior Research
The van Exter group has an extensive history of prior research in classical and quantum optics. As former part of the group of Han Woerdman, we have studied topics as diverse as:
Quantum noise in lasers
The stability of any laser is ultimately limited by quantum noise. We have studied the effect of quantum noise in semiconductor lasers, high-gain gas lasers, and Nd-doped solid state lasers to find among others: excess quantum noise, extreme relaxation oscillations, and intriguing polarization dynamics.
Polarization fluctuations in a laser can be describes as an evolution on the Poincaré sphere. These fluctuations are driven by quantum noise produced by spontaneous emission.
Quantum entanglement of photon pairs
We have studied the generation, propagation, and scattering of quantum-entangled photon pairs. Their spatial properties enable one to access a higher-dimensional quantum space and work with qudits instead of the common qubits. The Orbital Angular Momentum (OAM) proofs to be a relatively robust quantum number.
Two-photon speckle pattern observed behind two diffusors, which together mimic bulk scattering. The figure shows the coincidence count rate per second (in false colors) as a function of the two detector positions.
Metal hole arrays and surface plasmon lasers
Thin metal layers perforated with regular arrays of nanometer-size holes are convenient tools to generate and scatter surface plasmons. We have compensated their losses by adding a gain layer and studied the resulting surface plasmon lasing in various configurations and geometries.
Cavity QED with semiconductor quantum dots in micro pillars
Semiconductor quantum dots in monolithic oxide-confined micro pillar cavities can function as single-photon emitters and single-photon switches, where the quantum state of a single quantum dots determines whether the cavity transmits or reflect the light. We have studied both applications in the past. This research is continued and improved by Wolfgang Löffler.