Low cost ODMR attachment for commercial EPR spectrometers

The low-cost device for optical detection of magnetic resonance (ODMR) has been developed for use with commercial electron paramagnetic resonance spectrometers. The equipment is based on a scheme with coaxial optical fibers, where the excitation is transmitted through a central fiber with a diameter of 400 µ m, and the photoluminescence signal is collected using seven optical fibers with a diameter of 200 µ m. The device has the ability to modulate the excitation radiation, microwave frequency and magnetic field. The ODMR attachment has been tested on standard and well-known NV − (nitrogen-vacancy) paramagnetic centers in diamonds. ODMR experiments were carried out in the X-band (9.4 GHz) frequency range with a magnetic field B 0 sweeping from 220 to 470 mT. The best signal-to-noise ratio was obtained by modulating of the magnetic field. PACS: 07.57.Pt, 42.55.f, 42.60.by