FLASH 300™

The new FLASH 300™ is a stand-alone cuvette holder designed for laser experiments such transient absorbance, flash photolysis, fluorescence, and pulsed-laser photoacoustics. The FLASH 300™ differs from the earlier FLASH 200™ in two main ways. The FLASH 300™ is flattened in one dimension to permit easier access for focusing light. It is also shorter, making it easier to use with a laser producing light closer to the table.


Figure 1. Photograph of a FLASH 300 in a partially extended state

Click here for a .pdf file of a wireframe drawing showing dimensions of the FLASH 300.

Description
The FLASH 300™ cuvette holder consists of an insulated, temperature-controlled housing which holds a standard 1-cm square cuvette. The temperature-controlled tower is rectangular in cross section. Collimated light sources may be directed through the long dimension. The shorter dimension permits optical access at greater angles. This is useful for experiments requiring multiple laser beams at different angles, or the focusing or collection of uncollimated light. Optical ports are 10 mm wide by 12 mm high, and may be fitted with slits to limit stray light and to further enclose the sample for temperature control. A vertical translation assists in matching sample height with the laser beam, and the distance between the optical center line and the mounting surface may be adjusted over the range of 85 to 113 mm. A micrometer-driven horizontal adjustment permits fine adjustments of the position laser beams passing through the cuvette. Variable speed magnetic stirring is provided. A removable access plug provides direct access to the surface of the cuvette for mounting transducers or specialized optics. A dry gas purging system keeps cuvette surfaces free of condensation and further purges under the opaque lid, isolating the top of the cuvette from the ambient environment.



Figure 2. The FLASH 300 with components labeled

A windowed jacket is available for use at temperature extremes.



Figure 3. Windowed jacket with four AR-coated fused silica windows surrounding the cuvette

Performance Optional Components
The serial control option was used to automatically cycle the FLASH 300™ through a series of temperatures. The solid line shows the resulting temperature of the sample holder next to one of the optical ports. The dashed line shows the temperature measured inside a cuvette containing ethylene glycol and water.



Photoacoustics Option
The photoacoustics option for the FLASH 300™ provides a pressure mechanism that holds a piezoelectric transducer and mounts against one window of the cuvette. To set up the photoacoustics option, the cuvette is first placed in the cuvette holder. The transducer is then placed in the pressure mechanism and a small amount (~5 microL) of a couplant such as mineral oil is applied to the active surface of the transducer. The resulting assembly is screwed to the side of the sample holder covering one of the optical ports. An insulating cover is applied to the outside of the pressure mechanism to maintain the transducer at the same temperature as the cuvette. To remove the cuvette after completing the measurement, the insulating cover is removed, and a release knob is used to remove the pressure from the transducer.



Sample Holder Temperature Ranges