Electrically pumped widely tunable O-band hybrid lithium niobite/III-V laser

Abstract

Significant improvements in the lithium niobate on insulator (LNOI) platform are pushing LNOI-based laser sources to the forefront of integrated photonics. Here, we report the first, to the best of our knowledge, electrically pumped hybrid lithium niobate/III-V laser by butt coupling an InP-based optical gain chip with a LNOI photonic integrated circuit (PIC). In the PIC, a Vernier filter consisting of two LNOI microring resonators is employed to select the lasing wavelength. A wavelength tuning range of more than 36 nm is achieved in the O band. The hybrid laser has a maximum on-chip optical power of 2.5 mW and threshold current density of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mn>2.5</mml:mn> <mml:mspace width="thickmathspace"/> <mml:msup> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mi mathvariant="normal">k</mml:mi> <mml:mi mathvariant="normal">A</mml:mi> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mo>/</mml:mo> </mml:mrow> <mml:mi mathvariant="normal">c</mml:mi> <mml:mi mathvariant="normal">m</mml:mi> </mml:mrow> <mml:mn>2</mml:mn> </mml:msup> </mml:math> . A side mode suppression ratio better than 60 dB is achieved.