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Kicking the habit/semiconductor lasers without isolators

Harfouche, Mark and Kim, Dongwan and Wang, Huolei and Santis, Christos T. and Zhang, Zhewei and Chen, Hetuo and Satyan, Naresh and Rakuljic, George and Yariv, Amnon (2020) Kicking the habit/semiconductor lasers without isolators. Optics Express, 28 (24). pp. 36466-36475. ISSN 1094-4087.

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In this paper, we propose and demonstrate a solution to the problem of coherence degradation and collapse caused by the back reflection of laser power into the laser resonator. The problem is most onerous in semiconductor lasers (SCLs), which are normally coupled to optical fibers, and results in the fact that practically every commercial SCL has appended to it a Faraday-effect isolator that blocks most of the reflected optical power preventing it from entering the laser resonator. The isolator assembly is many times greater in volume and cost than the SCL itself. This problem has resisted a practical and economic solution despite decades of effort and remains the main obstacle to the emergence of a CMOS-compatible photonic integrated circuit technology. A simple solution to the problem is thus of major economic and technological importance. We propose a strategy aimed at weaning semiconductor lasers from their dependence on external isolators. Lasers with large internal Q-factors can tolerate large reflections, limited only by the achievable Q values, without coherence collapse. A laser design is demonstrated on the heterogeneous Si/III-V platform that can withstand 25 dB higher reflected power compared to commercial DFB lasers. Larger values of internal Qs, achievable by employing resonator material of lower losses and improved optical design, should further increase the isolation margin and thus obviate the need for isolators altogether.

Item Type:Article
Related URLs:
URLURL TypeDescription
Harfouche, Mark0000-0002-4657-4603
Kim, Dongwan0000-0002-5661-2503
Wang, Huolei0000-0001-6245-8090
Santis, Christos T.0000-0001-8636-1613
Zhang, Zhewei0000-0002-1211-7957
Chen, Hetuo0000-0003-1875-5041
Additional Information:© 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement. Received 6 Oct 2020; revised 6 Nov 2020; accepted 7 Nov 2020; published 16 Nov 2020. Funding: Defense Advanced Research Projects Agency (N66001-14-1-4062); Army Research Office (W911NF-14-P-0020, W911NF-15-1-0584, W911NF-16-C-0026). The authors declare no conflicts of interest.
Funding AgencyGrant Number
Defense Advanced Research Projects Agency (DARPA)N66001-14-1-4062
Army Research Office (ARO)W911NF-14-P-0020
Army Research Office (ARO)W911NF-15-1-0584
Army Research Office (ARO)W911NF-16-C-0026
Issue or Number:24
Record Number:CaltechAUTHORS:20201217-160839807
Persistent URL:
Official Citation:Mark Harfouche, Dongwan Kim, Huolei Wang, Christos T. Santis, Zhewei Zhang, Hetuo Chen, Naresh Satyan, George Rakuljic, and Amnon Yariv, "Kicking the habit/semiconductor lasers without isolators," Opt. Express 28, 36466-36475 (2020)
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:107181
Deposited By: George Porter
Deposited On:18 Dec 2020 15:32
Last Modified:18 Dec 2020 15:32

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