High- Q Optical Sensors for Chemical and Biological Analysis

Low threshold lasers based on rare-earth elements have enabled numerous scientific discoveries and innovations in industry. However, pushing the threshold into the sub-microwatt regime has been stymied by a fundamental material phenomenon. Specifically, rare earth dopants form clusters which quench emission and reduce efficiency. Here, we fabricate resonant cavity lasers from neodymium-doped silica films containing alumina. The alumina prevents the clustering of the Neodymium, enabling the lasers to achieve thresholds of 530nanoWatts at room temperature.

Section: Resultsmentioning

confidence: 99%

Nanowatt threshold, alumina sensitized neodymium laser integrated on silicon

Maker

Armani

2013

“…Resonant cavity-based detection relies on the dependence of the resonant wavelength on the cavity's refractive index and geometrical parameters [18,19]. Previous work has demonstrated cavity-based sensing using a variety of mechanisms (e.g.…”

Section: Temperature Detectionmentioning

confidence: 99%

Temperature sensor based on a hybrid ITO-silica resonant cavity

Socorro¹,

Soltani²,

Villar³

et al. 2015

Integrated optical devices comprised of multiple material systems are able to achieve unique performance characteristics, enabling applications in sensing and in telecommunications. Due to ease of fabrication, the majority of previous work has focused on polymerdielectric or polymer-semiconductor systems. However, the environmental stability of polymers is limited. In the present work, a hybrid device comprised of an indium tin oxide (ITO) coating on a silicon dioxide toroidal resonant cavity is fabricated. Finite element method simulations of the optical field in the multi-material device are performed, and the optical mode profile is significantly altered by the high index film. The quality factor is also measured and is material loss limited. Additionally, its performance as a temperature sensor is characterized. Due to the high thermo-optic coefficient of ITO and the localization of the optical field in the ITO layer, the hybrid temperature sensor demonstrates a nearly 3-fold improvement in performance over the conventional silica device.

“…Molded polydimethylsiloxane (PDMS) constitutes the current academic solution for silicon photonic biosensor microfluidics [10], but drawbacks such as large wafer area consumption, long curing times, adsorption of small biomolecules into the PDMS, and lack of bonding techniques compatible with surface biofunctionalization, make industrial application questionable [10]. These limitations are apparent in [11], in which stamping with an epoxy glue for bonding results in channel clogging.…”

Section: Introductionmentioning

confidence: 99%

Integration of microfluidics with grating coupled silicon photonic sensors by one-step combined photopatterning and molding of OSTE

Errando-Herranz¹,

Saharil²,

Romero³

et al. 2013

We present a novel integration method for packaging silicon photonic sensors with polymer microfluidics, designed to be suitable for wafer-level production methods. The method addresses the previously unmet manufacturing challenges of matching the microfluidic footprint area to that of the photonics, and of robust bonding of microfluidic layers to biofunctionalized surfaces. We demonstrate the fabrication, in a single step, of a microfluidic layer in the recently introduced OSTE polymer, and the subsequent unassisted dry bonding of the microfluidic layer to a grating coupled silicon photonic ring resonator sensor chip. The microfluidic layer features photopatterned through holes (vias) for optical fiber probing and fluid connections, as well as molded microchannels and tube connectors, and is manufactured and subsequently bonded to a silicon sensor chip in less than 10 minutes. Combining this new microfluidic packaging method with photonic waveguide surface gratings for light coupling allows matching the size scale of microfluidics to that of current silicon photonic biosensors. To demonstrate the new method, we performed successful refractive index measurements of liquid ethanol and methanol samples, using the fabricated device. The minimum required sample volume for refractive index measurement is below one nanoliter.