Andor introduced solid state laser combiner technology in 2005, just as solid state lasers were becoming established as viable alternatives to gas lasers. Our goal was to introduce a product with small footprint (physical, electrical and environmental), modular design for flexibility and best-in-class performance. The ALC-400 series is the result providing a highly robust modular framework to integrate up to 4 solid state laser modules, an integrated acousto-optic tunable filter (AOTF), delivering visible laser light with high efficiency (60-80%) through single mode optical fiber(s) and has such a rugged opto-mechanical design that once installed rarely if ever requires re-alignment. The entire unit fits into a standard laboratory 19” rack as shown above.
The fully loaded combiner, consumes only a few hundred watts, operates in a standard laboratory environment and covers the visible spectrum from 405 to 640 nm. This makes it an ideal source for applications such as confocal and TIRF microscopy.
Several variations on the ALC-400 series have been developed, including the ALC-421 which provides a means to combine solid state lasers with the 488 and 514 nm lines of an Argon ion gas laser, which proves a popular choice.
Solid state laser lines are available in the following wavelengths:
405, 445, 488, 491, 514, 561, 640 nm.
Power levels of the SS laser modules vary in the range 25-100 mW, which covers even the most power hungry imaging and activation requirements. Not all wavelengths are available at all powers.
New laser modules are brought to market continually and there may be new choices available even now. So please enquire if you have a special request for a specific wavelength or power level.
Figure 1 - ALC and Multi-Port Switch (MPS)
In order to use the same laser lines for multiple imaging modes, we have developed a proprietary multi-port switch (MPS), which delivers 100% of laser power to one of three fiber delivery ports,as shown in the figure 1. MPS uses a fast galvanometer to switch outputs in approximately 1 ms, with external TTL control. Stability is remarkably good, typically ~ 0.5% over a 12 hour period. This includes SS laser long term intensity fluctuations. The rapid performance of MPS ensures that switching between imaging modes is not limited by the ALC, but other factors in the system. Used with our FRAPPA configuration, switching between CSU imaging and FRAPPA takes <5 ms including delays induced by software latency and camera triggering. This represents best in class performance.
The figures above show measured switching delay, rise time and long term stability of the MPS under Andor iQ control. On the top graph the measured latency < 5ms (~ 3ms in this case) and the signal rise time is about 500 us (10-90%), as predicted from the design specifications. Best performance in analytical microscopy demands that coupling to the 2 (or 3) output fibers should be both stable and efficient. On the bottom graph we see a power stability curve for one output plotted overnight (14 hours), where the unit was switched every two minutes and sampled every 30 seconds. Peak to peak fluctuation was approximately -2% to +4%, which compares well to the SS module stability of +/- 3% over 8 hours. Note that the largest fluctuations correspond to the timing of AC switch off for the night (+2.5 hrs) and switch on for the morning (+12.5 hrs). In a more stable room temperature (4-12 hrs) stability is around +/- 1% peak. The efficiency of the Andor MPS is high.For example, a typical coupling efficiency value for each of the three ports is 80%(+0/-10%) at 488nm.
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