Reconfigurable Solid-state Dye-doped Polymer Ring Resonator Lasers.

Hengky Chandrahalim,Xudong Fan

doi:10.1038/srep18310

Abstract

This paper presents wavelength configurable on-chip solid-state ring lasers fabricated by a single-mask standard lithography. The single- and coupled-ring resonator hosts were fabricated on a fused-silica wafer and filled with 3,3′-Diethyloxacarbocyanine iodide (CY3), Rhodamine 6G (R6G), and 3,3′-Diethylthiadicarbocyanine iodide (CY5)-doped polymer as the reconfigurable gain media. The recorded lasing threshold was ~220 nJ/mm2 per pulse for the single-ring resonator laser with R6G, marking the lowest threshold shown by solid-state dye-doped polymer lasers fabricated with a standard lithography process on a chip. A single-mode lasing from a coupled-ring resonator system with the lasing threshold of ~360 nJ/mm2 per pulse was also demonstrated through the Vernier effect. The renewability of the dye-doped polymer was examined by removing and redepositing the dye-doped polymer on the same resonator hosts for multiple cycles. We recorded consistent emissions from the devices for all trials, suggesting the feasibility of employing this technology for numerous photonic and biochemical sensing applications that entail for sustainable, reconfigurable, and low lasing threshold coherent light sources on a chip.

Highlights

Since the pioneering work back in the 1960s and 1970s1–4, solid-state dye-doped polymer lasers have found many applications in optical communication devices[5], advanced nanoscale lasers[6], biosensing[7,8,9], and novel integrated photonic systems on-chip[10]
The lowest recorded lasing threshold is ~220 nJ/mm[2] per pulse for the multimode single-ring cavity with Rhodamine 6G (R6G)-doped SU-8
It should be emphasized that several fabrication methods, especially those applied to realize Bragg gratings and photonic crystal based cavities, require serial writings by e-beam lithography, which can be very time consuming and lead into astronomical fabrication costs when large arrays of devices on the substrate are needed

Summary

Introduction

Since the pioneering work back in the 1960s and 1970s1–4, solid-state dye-doped polymer lasers have found many applications in optical communication devices[5], advanced nanoscale lasers[6], biosensing[7,8,9], and novel integrated photonic systems on-chip[10]. The micro-ring and micro-disk optical cavities that operate based on the whispering gallery modes (WGM) are recognized to have relatively high quality factors (Q-factors) even if they are manufactured on a chip[8,25,26,27] They have a simple geometrical shape, small footprint, and ability to accommodate a broad range of lasing emission wavelengths. Bog et al demonstrated the multiplexed deposition of different functionalization coatings on neighboring goblet structures[7,9] While this method shows the great potential to manufacture solid-state lasers economically[8], it lacks the accuracy to define the final shape and size of the ring resonators after the reflowing process. Such methods pose a limitation to precisely define the final dimensions of the resonators and/or have difficulty in controlling the gap between the two rings in a coupled ring resonator system

Methods

Results

Conclusion