arXiv subjects

Joscelyn van der Veen

Publications and source records attributed to Joscelyn van der Veen.

6 recordsLinked to original sources

arXiv2026

Density Matrices of Pulsed Quantum Light

Pulsed light is represented by density matrices whose correlation functions have different properties of stationarity and coherence. We show that these density matrices yield equivalent measurement results after accounting for finite detection times. This in turn reveals a physical meaning to the length of a quantization cavity and explains the origin of the physical spectrum for pulsed light. By generalizing the density matrices for pulsed Gaussian states of light, we can describe pulsed light of varying statistics in the same basis and relate the photocount rate to the pulse spectrum.

quant-ph↗

arXiv2025

Effects of time dependence in the second order coherence of pulsed light

For light in a single temporal mode, the time dependence is associated entirely with the deterministic pulse shape rather than the quantum state. This means the second order coherence of light can no longer be understood as the temporal distribution of photons. We calculate the distribution of photon arrival time differences for pulsed light and find that it is inherently strongly bunched in terms of photocount arrival time differences. We further show how to account for the pulse shape when determining the second order coherence that characterizes quantum states.

quant-ph↗

arXiv2025

Errors in quantum state identification with ultrashort pulses

From the nonclassicality of photon superbunching to the basic property of intensity, we characterize light with correlation and coherence functions. The correlation functions for nonstationary sources, such as short pulses, depend deterministically on the time dependent shape of the field and change the probability of the ensemble in time. We start from the fundamental principles of detection and show how nonstationary fields result in a coherence function that depends not only on the statistics of the field but also on the field shape. This means that observations of bunching and superbunching with ultrafast sources are not indicative of the quantum state of the field.

quant-ph↗

arXiv2024

Averages in optical coherence: resolving the Magyar and Mandel-Wolf paradox

The ubiquity of optical coherence arising from its importance in everything from astronomy to photovoltaics means that underlying assumptions such as stationarity and ergodicity can become implicit. When these assumptions become implicit, it can appear that two different averages are independent: the finite time averaging of a detector and the ensemble average of the optical field over multiple detections. One of the two types of averaging may even be ignored. We can observe coherence as an interference fringe pattern and learn properties of the field through both methods of averaging but the coherence will not be the same, as demonstrated by the Magyar and Mandel-Wolf paradox.

quant-ph↗

arXiv2023

Analytic spectrum of multi-frequency Raman generation with chirped pulses

Multi-frequency Raman generation is a promising method of producing ultrashort laser pulses with high intensities and visible wavelength frequencies. In experimental realizations of multi-frequency Raman generation the Raman order peaks display several behaviours that are not explained by the current theory. We derive an analytic and perturbative expression for the spectrum radiated by a Raman medium excited by multiple Gaussian laser pulses and show that it qualitatively agrees with experimental observations.

physics.optics↗

arXiv2021

Interaction of a heralded single photon with nitrogen-vacancy centers in a diamond

A simple, room-temperature, cavity- and vacuum-free interface for a photon-matter interaction is implemented. In the experiment, a heralded single photon generated by the process of spontaneous parametric down-conversion is absorbed by an ensemble of nitrogen-vacancy color centers. The broad absorption spectrum associated with the phonon sideband solves the mismatch problem of a narrow absorption bandwidth in a typical atomic medium and broadband spectrum of quantum light. The heralded single photon source is tunable in the spectral range 452-575 nm, which overlaps well with the absorption spectrum of nitrogen-vacancy centers.

quant-ph↗