The BORGG Sensor: Cr³⁺-Doped Fractal Borosilicate with Bragg-Optimized Photon Emission

This paper introduces the BORGG (Bragg-Optimized Reflective Glass Generator), a room-temperature quantum sensor constructed from Cr³⁺-doped borosilicate glass and integrated dielectric Bragg reflectors (DBRs). The design enables scalable single-photon emission with high coherence and low g²(0) noise, without requiring cryogenic temperatures or exotic materials. Fabricated using femtosecond fractal etching and low-cost materials, the BORGG sensor redefines accessibility, stability, and precision in quantum photonic systems. This work directly challenges the current reliance on hBN, diamond NV centers, and gold-mirrored substrates by demonstrating superior performance with a platform built from everyday materials; optimized with quantum-scale engineering.