Mid-infrared ultra-high-Q resonators based on fluoride crystalline materialsстатья
Статья опубликована в высокорейтинговом журнале
Информация о цитировании статьи получена из
Web of Science,
Scopus
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 30 декабря 2016 г.
Аннотация:The unavailability of highly transparent materials in the mid-infrared has been the
main limitation in the development of ultra-sensitive molecular sensors or cavity-based
spectroscopy applications. Whispering gallery mode microresonators have attained
ultra-high-quality (Q) factor resonances in the near-infrared and visible. Here we report
ultra-high Q factors in the mid-infrared using polished alkaline earth metal fluoride crystals.
Using an uncoated chalcogenide tapered fibre as a high-ideality coupler in the mid-infrared,
we study via cavity ringdown technique the losses of BaF2, CaF2, MgF2 and SrF2
microresonators. We show that MgF2 is limited by multiphonon absorption by studying the
temperature dependence of the Q factor. In contrast, in SrF2 and BaF2 the lower multiphonon
absorption leads to ultra-high Q factors at 4.5mm. These values correspond to an optical
finesse of F>10^5, the highest value achieved for any type of mid-infrared resonator
to date.