Quantum optics is the study of individual quanta of light (photons) to understand their behavior and use within photonics applications, such as computing, communications, and metrology. To further the development of the field, it is paramount for students to build a foundational understanding of quantum concepts and single photon interactions. However, these abstract concepts can be extremely difficult to grasp with standard lectures. Implementing practical hands-on demonstrations can allow students to visualize and interact with key quantum optics concepts and potentially expand their understanding.

Thorlabs has developed a Quantum Optics Educational Kit to offer educators a way to include quantum optics within laboratory courses to demonstrate the differences between classical and non-classical, “quantum” light sources with maximum student interaction. Interaction with the kit begins with the Hanbury Brown and Twiss (HBT) experiment, which is intended to show that attenuating a classical source, such as an alignment laser, with a neutral density (ND) filter will not result in the creation of a suitable single photon source before then moving on to setting up the quantum light source. For the quantum light source, the core components are a 405 nm pump laser and a nonlinear, type-I beta barium borate (BBO) crystal. When the pump laser is incident upon the BBO crystal, spontaneous parametric down conversion (SPDC) generates time-energy entangled photon pairs with an 810 nm wavelength. Once the quantum source is set up, the Grainger-Roger-Aspect experiment is performed and the second order correlation values are calculated in real time allowing for a comparison between the alignment laser and the quantum source. Following this milestone, users set up a Michelson interferometer to demonstrate single photon interference.  The interferometer is then modified by adding several polarizers to demonstrate a quantum eraser, utilizing polarization information to break down single photon interference.

Schedule:

Over the course of this three-day immersion, we will assemble subcomponents of the Thorlabs educational kit, populate the breadboard, and proceed through the core experimental procedures outlined in the kit’s manual.

Required Equipment:

            Laptop – Educational kit’s software package requires Windows® 10 or Higher (64-Bit) and four free USB 2.0 ports (or suitable USB hub).

Safety Considerations:

            The class 3B laser diode used in this kit can emit more than 50 mW of optical power, which can cause damage to the eyes if viewed directly. The laser driver is equipped with a key switch and safety interlock, which should be used appropriately to avoid injury. We will provide laser safety glasses and require their use when the laser is turned on.

Cost of Implementation:

            EDU-QOP1 - Quantum Optics Educational Kit, Imperial: $33,757.26