Taking the next step from individual functional components to higher integrated devices, we present a feasibility study of a lab-on-a-chip system with five different components monolithically integrated on one substrate. These five components represent three main domains of microchip technology: optics, fluidics and electronics. In particular, this device includes an on-chip optically pumped liquid dye laser, waveguides and fluidic channels with passive diffusive mixers, all defined in one layer of SU-8 polymer, as well as embedded photodiodes in the silicon substrate. The dye laser emits light at 576 nm, which is directly coupled into five waveguides that bring the light to five different locations along a fluidic channel for absorbance measurements. The transmitted portion of the light is collected at the other side of this cuvette, again by waveguides, and finally detected by the photodiodes. Electrical read-out is accomplished by integrated metal connectors. To our knowledge, this is the first time that integration of all these components has been demonstrated.

We present a single-mode, single-polarization, distributed feedback liquid dye laser, based on a short high-order Bragg grating defined in a single polymer layer between two glass substrates. In this device we obtain single-mode operation in a multimode structure by means of transverse-mode discrimination with antiguiding segments. The laser is fabricated using microfabrication technology, is pumped by a pulsed frequency-doubled Nd:YAG laser, and emits narrow-line-width light in the chip plane at 577 nm. The output from the laser is coupled into integrated planar waveguides defined in the same polymer _lm. The laser device is thus well suited for integration, for example, into polymer based lab-on-a-chip microsystems.

We present a laterally emitting, coupled cavity micro fluidic dye ring laser, suitable for integration into lab-on-a-chip micro systems. The micro-fluidic laser has been successfully designed, fabricated, characterized and modelled. The resonator is formed by a micro-fluidic channel bounded by two isosceles triangle mirrors. The micro-fluidic laser structure is defined using photo lithography in 10 µm thick SU-8 polymer on a glass substrate. The micro fluidic channel is sealed by a glass lid, using PMMA adhesive bonding. The laser is characterized using the laser dye Rhodamine 6G dissolved in ethanol or ethylene glycol as the active gain medium, which is pumped through the micro-fluidic channel and laser resonator. The dye laser is optically pumped normal to the chip plane at 532 nm by a pulsed, frequency doubled Nd:YAG laser and lasing is observed with a threshold pump pulse energy flux of around 55 µJ/mm 2 . The lasing is multi-mode, and the laser has switchable output coupling into an integrated polymer planar waveguide. Tuning of the lasing wavelength is feasible by changing the dye/solvent properties.

We present a polymer-based, microfluidic dye laser suitable for integration into polymer- or silicon-based lab-on-a-chip systems. The laser is fabricated by nanoimprint lithography (NIL) in cyclo-olefin copolymer (COC). The polymer device consists of microfluidic channels, with sizes ranging from several mm down to a few µm, and integrated optical waveguides to couple the light out of the structure, all fabricated in one single NIL step and with approximately 10 nm roughness. COC is a highly transparent, chemically resistant thermoplastic polymer optimal for the integration of microfluidic systems with optical elements. Rhodamine 6G dissolved in ethanol is used as an active medium in the laser, and the resonator is based on multiple reflections from a periodic structure of 16 µm wide, parallel microfluidic channels. Lasing from the device is observed at 577 nm, when optically pumped with a frequency doubled Nd:YAG laser emitting at 532 nm, where Rhodamine 6G has its absorption maximum.