Demonstrating long-term stable optical coupling between single-mode optical fibers and well-defined energy photons emitted from nitrogen impurity centers in GaAs flakes

Abstract

A key challenge in realizing scalable optical quantum information technology is not only to obtain stable single photons coupled to single-mode fibers but also to match the emission energy between remote emitters. We have fabricated an energy-matching favorable and long-term stable structure by coupling a nitrogen impurity center with a well-defined emission energy to a single-mode optical fiber core. The nitrogen-doped GaAs microflakes sandwiched between the two FC (acronym for "ferrule connector" or "fiber channel") connectors yielded sharp emission peaks due to nitrogen isoelectronic traps. Although some emitters showed spectral diffusion, the unaffected emitters showed stable emission and were able to generate photons stably for over 20 h continuously without photodegradation. In addition, the photoluminescence spectrum does not change in shape and intensity after more than 3 years, indicating that the photon source with this structure is resistant to thermal cycling and positional drift and has excellent long-term stability.