Ultra high-Q WGM microspheres from ZBLAN for the mid-IR band

Abstract

The advantages of high-quality-factor whispering gallery mode microresonators can be applied to develop novel photonic devices for the mid-IR range. ZBLAN (glass based on heavy metal fluorides) is one of the most promising materials to be used for this purpose due to low optical losses in the mid-IR. We developed original fabrication method based on melting of commercially available ZBLAN-based optical fiber to produce high-Q ZBLAN microspheres with the diameters of 250 to 350 $\mu$m. We effectively excited whispering gallery modes in these microspheres and demonstrated high quality factor both at 1.55 $\mu$m and 2.64 $\mu$m. Intrinsic quality factor at telecom wavelength was shown $(5.4\pm 0.4)\cdot 10^8$ which is defined by the material losses in ZBLAN. In the mid-IR at 2.64 $\mu$m we demonstrated record quality factor in ZBLAN exceeding $10^8$ which is comparable to the highest values of the Q-factor among all materials in the mid-IR.

References in corpus (2)

• Microresonator and Laser Parameters Definition via Self-Injection Locking
• Self-injection locking of the gain-switched laser diode