Despite being widely accepted, the physics of optical waves has some fundamental aspects that are debatable. One of these effects, the anomalous behavior of focused light fields, is being studied in a new light, a quantum light. Quantum light with a well-defined photon number behaves differently than standard focused laser beams, according to researchers. This discovery adds to their understanding of the phenomenon while allowing super-sensitive distance measurements.
Although the traditional description of light as a wave phenomenon is rarely called into question, the physical origins of some optical effects are. The researchers have moved the debate over one fundamental wave effect, namely the anomalous behavior of focused light waves, to the quantum domain.
They demonstrated that quantum waves behave significantly differently than their classical counterparts and can be used to improve distance measurement precision. The findings also contribute to the debate over the physical cause of anomalous focusing behavior.
The researchers began with an idea based on previous findings and set out to structure quantum light for improved measurement precision. However, they soon realized that the application’s underlying physics also contributed to the long debate over the origins of the Gouy phase anomaly of focused light fields.