All-optical thermometry using a single multimode fiber endoscope and diamond nanoparticles containing nitrogen...

Area of Science:

• Optics and Photonics
• Materials Science
• Quantum Information Science

Background:

• Diamond nanoparticles with nitrogen vacancy (NV) centers are promising for quantum sensing and information processing.
• Accurate characterization of NV centers, particularly their temperature dependence, is crucial for device applications.
• Existing spectroscopy methods can be complex and require specialized setups.

Purpose of the Study:

• To develop and validate a compact, fiber-based endoscope system for measuring photoluminescence (PL) from diamond nanoparticles.
• To investigate the temperature dependence of the zero-phonon line (ZPL) in NV centers within diamond nanoparticles.
• To demonstrate the feasibility of in-situ, temperature-controlled spectroscopy of quantum defects.

Main Methods:

• Utilized a single multimode fiber endoscope coupled to a high-sensitivity spectroscopy system.
• Generated a laser light spot at the endoscope's distal end for excitation.
• Measured PL spectra from temperature-controlled diamond nanoparticle ensembles.
• Calibrated the spectroscopy system's sensitivity and wavelength response.

Main Results:

• Successfully acquired photoluminescence spectra from diamond nanoparticles containing negative nitrogen vacancy centers.
• Obtained the temperature dependence of the zero-phonon line peak wavelength.
• The observed temperature dependence of the ZPL wavelength was consistent with previously reported data.

Conclusions:

• The fiber-coupled endoscope system provides a viable method for spectroscopy of diamond NV centers.
• The system enables temperature-dependent measurements crucial for understanding and utilizing NV center properties.
• This approach offers a pathway towards miniaturized and portable quantum sensing devices.