High-temperature and high-efficiency operation of a membrane optical link with a buried-ridge-waveguide bonded on a Si substrate

• Published in: Optics express 2022-09, Vol.30 (19), p.34420-34428
• Main Authors: Fang, Weicheng, Takahashi, Naoki, Horikawa, Tsuyoshi, Ohiso, Yoshitaka, Xue, Ruihao, Katsumi, Shunto, Amemiya, Tomohiro, Nishiyama, Nobuhiko
• Format: Article
• Language: English
• ISSN: 1094-4087; 1094-4087
• DOI: 10.1364/OE.468192

We demonstrate a membrane photonic integrated circuit (MPIC) that includes a membrane distributed feedback (DFB) laser and a p-i-n photodiode with a buried-ridge-waveguide (BRW) on a Si substrate, using a-Si nanofilm-assisted room-temperature surface activated bonding (SAB) for on-chip optical interconnection. The BRW structure enhanced the lateral optical confinement compared with that of the conventional flat structure. The directly bonded membrane DFB laser using SAB had a lower thermal resistance and higher output power than the previous structure using a benzocyclobutene (BCB) bonding layer. The DFB laser had a low threshold current of 0.27 mA at 25 °C. The maximum detected photocurrent and slope efficiency were 0.95 mA and 0.203 mA/mA, respectively, at 25 °C. The MPIC was successfully operated at temperatures up to 120 °C. The 3-dB bandwidths of 16.8 GHz and 10.1 GHz were achieved at 25 °C and 80 °C, respectively, and 25 Gbps and 15 Gbps non-return-to-zero (NRZ) 2 15 -1 pseudo-random bit sequence signals were recorded at 25 °C and 80 °C, respectively.