In cases where highest time resolution is essential, the IonOptix HyperSwitch Light Source is recommended. Wavelength switching is accomplished in less than 1msec and can be continuously alternated at rates as high as 250 pairs/sec. The HyperSwitch can also produce hardware video-locked wavelength switching.
This figure illustrates the optical path and components of the IonOptix HyperSwitch Dual Excitation Light Source. The light output of a 75 W xenon-arc bulb is formed into a converging beam using a parabolic reflector within the xenon housing. A front-surface beam steering mirror positions the focal point of the beam just beyond a galvo-driven mirror that rapidly alternates between two separate paths. In path 1, the now diverging xenon light is collimated by a quartz lens and is then steered into the “side” input of the excitation dichroic cube (EDC). In path 2, a second lens collimates the xenon light before it enters the “front” input of the EDC. In addition, the mirror may also be set to a third position that provides high speed shuttering of the excitation light by directing the light away from both input paths. Separate filters on each input of the EDC filter the xenon light to create the individual excitation wavelengths. A dichroic mirror inside the EDC passes the filtered path 2 light to the “rear” output of the EDC as well as reflects the filtered path 1 light to the same output. The output of the EDC is then focused on the end of a liquid light guide. The opposite end of the light guide is equipped with a microscope-coupling adapter thus presenting excitation light to the specimen. Microscope couplings are available for all commercial microscopes.
Two more recent innovations that are not illustrated in the figure are the Cube Flipper and the Filter Flipper. The cube flipper permits the EDC to be rotated out of the optical path so that all excitation light can be brought to the microscope. This feature permits quick alternation between dual excitation (i.e. fura-2) and single excitation (i.e. GFP) modes. The Filter Flipper is a manually controlled, 6-position filter wheel that is used to hold neutral density filters.
Excitation filters of your specification are included with each system and can be ordered as required.