Modulation of coherently coupled surface-emitting laser arrays: analysis and applications

Fryslie, Stewart T

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https://hdl.handle.net/2142/97293 Copy

Description

Title

Modulation of coherently coupled surface-emitting laser arrays: analysis and applications

Author(s)

Fryslie, Stewart T

Issue Date

2017-04-04

Director of Research (if dissertation) or Advisor (if thesis)

Choquette, Kent

Doctoral Committee Chair(s)

Choquette, Kent

Committee Member(s)

• Schutt-Ainé, José
• Goddard, Lynford
• Dragic, Peter

Department of Study

Electrical & Computer Eng

Discipline

Electrical & Computer Engr

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

Ph.D.

Degree Level

Dissertation

Keyword(s)

• Semiconductor lasers
• Phased arrays
• Vertical-cavity surface-emitting lasers
• Optical communications

Abstract

Vertical-cavity surface-emitting lasers (VCSELs) have become the dominant source for optical data communication links in computer server, data center, and super computer applications. Driven by the exponential increase of performance in information technology, data centers, and computational power, data transmission bandwidth is required to increase exponentially as well. Furthermore, as data centers become physically larger, utilizing more interconnects and requiring longer rack-to-rack fiber transmission distance, low power consumption and narrow spectral width for reduced signal dispersion become increasingly important. This work discusses the development of phased, ion-implanted, PhC VCSEL arrays for coherently coupled operation and modulation bandwidth enhancement with narrow spectral width emission. In this dissertation, monolithic mutual optical injection locking induced laser dynamics in phased, coherently coupled implant-defined PhC VCSEL arrays are investigated in detail both theoretically and experimentally. A model based on the well-established injection-locking laser rate equations is used to intuitively explain the physics of various experimental phenomena. An operation procedure, in which current isolation and bias conditions are leveraged to control array index profile and coupling phase, is developed to achieve coherently coupled operation of the phased VCSEL arrays reproducibly with high yield. An experimental study on the modulation characteristics and locking range dynamics of coherently coupled VCSEL arrays is conducted, showing significant improvements in operational procedures, performance, and device manufacturing. A record VCSEL 3 dB bandwidth of 37 GHz (receiver limited) is obtained under highly single-mode coherent operation with narrow spectral width and increased output power while the laser array is biased at low current density. Additionally, this result has been duplicated by multiple devices, under coherently coupled operation in either the in-phase or out-of-phase mode. Bandwidth enhancement beyond 30 GHz has been shown to be reproducible for several different photonic crystal patterns, and bias conditions for bandwidth enhancement have been shown to be stable and reproducible for the same device design across the sample.

Graduation Semester

2017-05

Type of Resource

text

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http://hdl.handle.net/2142/97293

Copyright and License Information

Copyright 2017 Stewart Fryslie

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