Dynamic and Spectral Features of Superluminescence under Optical Pumping at λ = 532 nm in Synthetic HPHT Diamond with NV¯ Centers
Vyacheslav F. Lebedev, E. A. Vasiliev, Ya. A. Ryvkina +4 more
Abstract— A comparative analysis has been made of the superluminescence spectra of two HPHT diamond samples with NV¯-centers with the concentration in the growth sectors {111} of NV¯-centers ≈10 ppm and of C-centers ≈ 45 ppm. A broad structureless superluminescence band with a maximum about 706 nm and a narrow band in the region of 705 to 720 nm were identified in the spectral range of 650–750 nm when excited by pulsed laser radiation at λ = 532 nm. It was found that the narrow-band superluminescence was not excited by pumping with continuous radiation at λ = 532 nm and the intensities of both types of superluminescence were summated under simultaneous pumping by continuous and pulsed radiation at λ = 532 nm. These data indicate either the different nature of the two types of superluminescence or that they belonged to NV¯ centers but with different excitation mechanisms. The existence of connection between the shape of the spectra of narrow-band superluminescence and of radiation pulses has been demonstrated. The observed features of narrow-band superluminescence are explained for the first time by the occurrence of mode-locking laser generation. The mode-locking laser generation without the use of reflective coatings on the sample or an external resonator on other laser materials has not been observed before.
Bulletin of the Lebedev Physics Institute•Dec 1, 2024•3 citations