Distributed feedback lasers based on green fluorescent protein and conformal high refractive index oxide layers
Abstract
Fluorescent proteins have emerged as an attractive gain material for lasers, especially for devices requiring biocompatibility. However, due to their optical properties, integration with distributed feedback (DFB) resonators is not readily achievable. Here, a DFB laser with enhanced green fluorescent protein (eGFP) as the gain material is demonstrated by incorporating a thin (65 nm), high refractive index (n = 2.12) ZrO2 interlayer as waveguide core. Deposition of ZrO2 via atomic layer deposition yields a smooth and conformal film as required to minimize optical losses. Lasing emission is obtained from 2D second‐order DFB eGFP lasers at pump power densities above 56.6 kW cm–2 and a wavelength tuning range of Δλ = 51.7 nm is demonstrated. Furthermore, it is shown that in contrast to conventional organic DFB lasers, both transverse electric (TE) and transverse magnetic (TM) modes are accessible. The effective refractive index of these modes can be predicted accurately through optical modelling. Using far‐field imaging, the laser beam profile is studied and TE and TM modes are distinguished.
Citation
Karl , M , Meek , A T , Murawski , C , Tropf , L C , Keum , C , Schubert , M , Samuel , I D W , Turnbull , G A & Gather , M C 2020 , ' Distributed feedback lasers based on green fluorescent protein and conformal high refractive index oxide layers ' , Laser & Photonics Reviews , vol. 14 , no. 6 , 2000101 . https://doi.org/10.1002/lpor.202000101
Publication
Laser & Photonics Reviews
Status
Peer reviewed
ISSN
1863-8880Type
Journal item
Description
Funding: European Research Council (ERC StG ABLASE, 640012). M.K. and A.M. acknowledge funding from the EPSRC DTG (EP/M506631/1 and EP/M508214/1). L.T. acknowledges studentship funding through the EPSRC CM-CDT (EP/L015110/1). M.S. acknowledges funding from the Royal Society (Dorothy Hodgkin Fellowship, DH160102). I.D.W.S. acknowledges funding from a Royal Society Wolfson research merit award.Collections
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