Abstract

Nonlinear devices have been essential for extending laser wavelength operating ranges since its invention. The ability to convert a laser’s wavelength between the telecoms C-band and 780 nm has attracted much attention recently due to the developments of magneto-optical traps using Rb aimed at high precision gravity measurements and quantum optics for generating entangled photon pairs. For magneto-optical traps the low linewidths and low cost optical components from well established telecoms technology have enabled the efficient generation of the small frequency shifts required to address the excitation states of the Rb. Nonlinear waveguides based on direct bonded lithium niobate on lithium tantalate have demonstrated high efficiency second harmonic generation (SHG) of telecoms lasers [1], but are difficult to fabricate. Ti indiffused PPLN waveguides have been shown as an alternative, but it has been shown recently that photorefraction limits the performance of these waveguides to less than 10 mW [2].

© 2019 IEEE