Optical amplitude and Phase Modulation Dynamics at the Single Photon Level in a Quantum Dot Ridge Waveguide
Galan A. Moody, Corey A. McDonald, Ari D. Feldman, Todd E. Harvey, Richard P. Mirin, Kevin L. Silverman
The amplitude and phase of a materials nonlinear optical response provide insight into the underlying electronic and exciton dynamics that determine its optical properties. Phase-sensitive nonlinear spectroscopy techniques are widely implemented to explore these dynamics through demodulation of the complex optical signal field into its quadrature components; however, complete reconstruction of the optical response requires measuring both the power and phase in each quadrature, which is often lost in standard detection methods. Here, we implement a phase-sensitive heterodyne-detection scheme to fully reconstruct the amplitude and phase response of spectral hole-burning from InAs/GaAs charged quantum dots. We observe an ultra-narrow spectral hole in the quantum dot absorption profile and a corresponding dispersive lineshape of the phase, which reflect the nanosecond optical coherence time of the charged exciton transition. Simultaneously, the measurements are sensitive to electron spin relaxation dynamics on a millisecond timescale, as this manifests as a magnetic-field dependent delay of the amplitude and phase modulation. Appreciable amplitude modulation depth and nonlinear phase shift up to ~0.09×pi (16°) are demonstrated, providing new possibilities for quadrature modulation at faint photon levels using quantum dots with several independent control parameters, including photon number, modulation frequency, detuning, and externally applied fields.
, McDonald, C.
, Feldman, A.
, Harvey, T.
, Mirin, R.
and Silverman, K.
Optical amplitude and Phase Modulation Dynamics at the Single Photon Level in a Quantum Dot Ridge Waveguide, Optica, [online], https://doi.org/10.1364/OPTICA.3.001397
(Accessed November 30, 2023)