We investigate macroscopic polymer lenses (0.5- to 2.5-cm diameter) fabricated by dropping hydrophobic photocurable resin onto the surface of various hydrophilic liquid surfaces. Due to the intermolecular forces along the interface between the two liquids, a lens shape is formed. We find that we can vary the lens geometry by changing the region over which the resin is allowed to spread and the surface tension of the substrate to produce lenses with theoretically determined focal lengths ranging from 5 to 25 mm. These effects are varied by changing the container width, substrate composition, and substrate temperature. We present data for five different variants, demonstrating that we can control the lens dimensions for polymer lens applications that require high surface quality.
Optical microcavities are used in variety of applications ranging from sensors to lasers and signal routing in high volume
communication networks. Achieving a high quality factor (Q) is necessary for achieving the higher sensitivity in sensing
applications and for narrow linewidth light emission in most lasing applications. In this work, we propose a new way for
achieving a higher quality factor in thin film, Fabry-Perot polymeric optical resonators. We show that lateral photon
confinement in a vertical Fabry-Perot microcavities can be achieved by optical writing of a refractive index profile
utilizing our UV-sensitive polymer. This method can improve the quality factor by one or more orders of magnitudes. In
order to demonstrate this improvement, the device has been fabricated. The fabricated device consists of two dielectric
Bragg reflectors with a layer of 100 μm thick polymer layer between them. The polymer is a thiol-ene/methacrylate
photopolymer whose optical index can be modified utilizing standard photo-lithography processes. The refractive index
of this polymer can be modified utilizing standard photo-lithography processes. The measured finesse of the fabricated
device was 692 and the quality factor was 55000. The achieved finesse combined with the flexible polymer layer allows
this device to be used as an ultrasound detector in optical micromachined ultrasound transducers (OMUT).
We present a thiol-ene/methacrylate-based polymer capable of creating both physical fluidic features and optical index
features via a series of three UV mask-lithography steps. The process of creating the two types of features are addressed
independently by control of the polymerization and diffusion rates within the polymer system. The rapidly curing
methacrylate creates a gelled, rubbery scaffold structure that allows for the creation of physical features and also
monomer diffusion within the structure. The thiol-ene is a high-index polymer that cures more slowly in the presence of
the methacrylate and is used to create the index structures via diffusion of replacement monomer into exposed regions.
We demonstrate low-loss, multi-mode optical waveguides coupled to a fluidic channel to implement a refractometer.
Waveguide loss at 635 nm for a 12.5 mm x 63.5 micron x 63.5 micron waveguide-only sample is 0.57 dB. A waveguide
plus fluidic-channel device acts as a refractometer whose optical throughput is dependent on the index of refraction of
the fluid in the channel.