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Probing material absorption and optical nonlinearity of integrated photonic materials

Gao, Maodong and Yang, Qi-Fan and Ji, Qing-Xin and Wang, Heming and Wu, Lue and Shen, Boqiang and Liu, Junqiu and Huang, Guanhao and Chang, Lin and Xie, Weiqiang and Yu, Su-Peng and Papp, Scott B. and Bowers, John E. and Kippenberg, Tobias J. and Vahala, Kerry J. (2021) Probing material absorption and optical nonlinearity of integrated photonic materials. . (Unpublished)

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Optical microresonators with high quality (Q) factors are essential to a wide range of integrated photonic devices. Steady efforts have been directed towards increasing microresonator Q factors across a variety of platforms. With success in reducing microfabrication process-related optical loss as a limitation of Q, the ultimate attainable Q, as determined solely by the constituent microresonator material absorption, has come into focus. Here, we report measurements of the material-limited Q factors in several photonic material platforms. High-Q microresonators are fabricated from thin films of SiO_2, Si_3N_4, Al_(0.2)Ga_(0.8)As and Ta_2O_5. By using cavity-enhanced photothermal spectroscopy, the material-limited Q is determined. The method simultaneously measures the Kerr nonlinearity in each material and reveals how material nonlinearity and ultimate Q vary in a complementary fashion across photonic materials. Besides guiding microresonator design and material development in four material platforms, the results help establish performance limits in future photonic integrated systems.

Item Type:Report or Paper (Discussion Paper)
Related URLs:
URLURL TypeDescription Paper
Yang, Qi-Fan0000-0002-7036-1712
Ji, Qing-Xin0000-0002-6336-8350
Wang, Heming0000-0003-3861-0624
Wu, Lue0000-0002-7503-7057
Shen, Boqiang0000-0003-0697-508X
Chang, Lin0000-0001-5311-3349
Yu, Su-Peng0000-0003-1348-7447
Papp, Scott B.0000-0001-8290-7076
Bowers, John E.0000-0003-4270-8296
Kippenberg, Tobias J.0000-0002-3408-886X
Vahala, Kerry J.0000-0003-1783-1380
Additional Information:Attribution 4.0 International (CC BY 4.0). The authors thank H. Blauvelt and Z. Yuan for helpful comments, Z. Liu for discussions on data processing, as well as D. Carlson for preparing the Ta2O5 SEM image. Q.-X. J. acknowledges the Caltech Student Faculty Program for financial supports. This work was supported by DARPA under the DODOS (HR0011-15-C-0055) and the APHi (FA9453-19-C-0029) programs. Author contributions. M.G., Q.-F.Y., Q.-X.J. and J.L. conceived the idea. M.G., Q.-F.Y. and Q.-X.J. performed the measurement with assistance from H.W., L.W., and B.S.. M.G., Q.-F.Y., Q.-X.J. and H.W. devised the theoretical model. L.W. provided the SiO_2 samples. J.L. and G.H. provided the Si_3N_4 samples. L.C. and W.X. provided the Al_(0.2)Ga_(0.8)As samples. S.-P.Y. provided the Ta_2O_5 samples. All the authors analyzed the data and wrote the manuscript. K.J.V., T.J.K., J.E.B. and S.B.P. supervised the project. Data availability. All data generated or analysed during this study are available within the paper and its supplementary materials. Further source data will be made available upon reasonable request. Code availability. The analysis codes will be made available upon reasonable request. The authors declare no competing financial interests.
Funding AgencyGrant Number
Caltech Summer Undergraduate Research Fellowship (SURF)UNSPECIFIED
Defense Advanced Research Projects Agency (DARPA)HR0011-15-C-0055
Defense Advanced Research Projects Agency (DARPA)FA9453-19-C-0029
Record Number:CaltechAUTHORS:20211130-215754289
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:112114
Deposited By: George Porter
Deposited On:30 Nov 2021 23:39
Last Modified:30 Nov 2021 23:39

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