Optical properties of transparent silicon carbide (SiC) are attracting increasing attention due to its large bandgap,electronic properties, hardness and ability to work at high electrical power, qualities that make it a key material forsensors and electronic devices. Silicon carbide has only been recently discovered as a photonics material, as well forapplications in opto-mechanics. Further, fluorescent color centers that can produce single photon sources and spinqubits have been recently found relevant in applications in quantum technologies, as potential building block of theirelements. Additionally, applications are in sensitive magnetometry and thermometry. Most of the optically andspin active color centers in SiC are vacancies related emitters, such as the simplest silicon mono-vacancy (V_(Si)).Other vacancies related emission bands are due to complex vacancies structures such as the carbon antisite vacancy pairs(CAV) and divacancies (V_(Si)V_C). These color centers can be generated by electrons, ions, neutrons,proton irradiation and focused ion beams with subsequent annealing at specific temperatures to facilitate thediffusion of vacancies to form in order V_(Si), CAV and V_(Si)V_C, depending on the annealing temperature of 400°C, 900°Cand 1000°C, respectively. To advance technological applications, it will be necessary to integrate such color centerswithin optical and electronic components by, positioning them at the desired locations with an accuracy from 10 nm to 1μm. There are only few examples so far of integrated color centers in SiC nano-particles. Their localization in thematerial with the above described techniques is however still challenging, limited by ions struggle, creating residualdamage to the crystal lattice and degrading the properties of the color center. Other methods are sought after for a morecontrolled formation of defects with a control over their 3D spatial positioning. Recently, another successful method tocreate color centers in optical material has been based on the use of femtosecond laser writing, whereas single colorcenters in diamond and boron nitride were demonstrated, More recently a similar technique was used tocreate silicon mono-vacancies in SiC with the atomic precision of the single emitter level. The advantages ofusing femtosecond lasers for micro and nano-machining of bulk optical transparent materials, i.e. materials that do nothave any linear absorption at the wavelength of the femtosecond laser, rely on the possibility to fabricate geometricallycomplex structures in three dimensions, in compound substrates of different materials, with the possibility of fabricationof an ‘optical motherboard’, where electronic and photonic interconnects are fabricated.
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