2026-10-14T09:26:24Z https://api.figshare.com/v2/oai

oai:figshare.com:article/34046832 2026-10-01T16:00:53Z category_37476 portal_1023 item_type_12 month_year_10_2026

Optically-Induced Modulation and Programming of Diamond Photonic Cavities Yuchun Zhu (5940395) Amirali Arabmoheghi (9352826) Nicolas Le Thomas (17494623) Niels Quack (3961370) Valentin Goblot (4995227) Christophe Galland (1781653) Physics (arXiv) physics.optics (arXiv) cond-mat.mes-hall (arXiv) quant-ph (arXiv) Single-crystal diamond combines exceptional optical, thermal, and mechanical properties while hosting optically addressable and spin-coherent colour centres, making it a promising platform for integrated quantum and nonlinear photonics. However, practical post-fabrication mechanisms for dynamically controlling and tuning monolithic diamond photonic circuits remain limited. Here, we demonstrate all-optical modulation and long-lived tuning of suspended diamond Fabry--Perot nanobeam cavities containing nitrogen-vacancy centres. Under 532~nm illumination, the infrared (1000 to 1100~nm) cavity response is governed by two competing contributions: a well-understood thermo-optic red-shift, and a novel charge-mediated blue-shift that we attribute to the free-carrier plasma dispersion effect. With 10~mW of 20~kHz-modulated green light, we achieve an infrared modulation depth of approximately 45\% of the available reflection contrast. Green illumination also produces quasi-permanent photo-refractive resonance blue-shifts, with a maximum observed tuning of 3.15~nm (0.87~THz), without measurable degradation of the cavity linewidth or contrast. Achieving the same cavity shift in a lithium-niobate Pockels modulator would require 200 to 500~V across a \(5~μ\mathrm{m}\) electrode gap. These results establish a monolithic diamond nanophotonic platform combining agile and reversible modulation with long-lived optical reconfiguration, two key ingredients in photonic technologies. 2026-09-29T00:00:00Z Text Preprint 10.48550/arXiv.2609.37163 https://figshare.com/articles/preprint/Optically-Induced_Modulation_and_Programming_of_Diamond_Photonic_Cavities/34046832 CC0