Mesoscopic photonic structures in glasses by femtosecond-laser fashioned confinement of semiconductor quantum dots

Optically tunable mesoscale structures offer unparalleled potential for photonic device applications. Here, we report the creation of composite photonic structures consisting of CdS xSe1−x quantum dots (QDs) customized within lines, first written in a glass by femtosecond laser pulses. CdS xSe1−x-doped borosilicate glasses were pulsed with a fs-laser using a 473 kHz repetition rate to create chemically distinct microscopic regions. Upon further heat treatment, these regions served as “micro-crucibles” within which quantum dots were precipitated exclusively. These results open prospects of developing other semiconductor doped glasses for versatile photonic structures useful over broader optical wavelengths.