Re: Suggestions on variable DC power supplies.
Well, linear regulators waste quite a bit of power and will need overhead which may inhibit your ability to produce HV for certain applications. Not sure if it is relevant to lasers or not.
If your application is sensitive to EMI Noise or supply noise, go for linear. Certain LDO ICs [not sure if they come preassembled into bench supplies] can produce as small as 20uVrms at the output. I know of no SMPS that can get anywhere near that even with secondary filtering.
Another is size, how big is your workbench?
A 50W linear power supply is typically 3 x 5 x 6”, whereas a 50W switch-mode can be as small as 3 x 5 x 1”. That’s a 80% size reduction. On account of weight a 1000W Linear will need two guys, a hand truck, and some back-braces to install. A 2000W switcher can fit in a suitcase.
I'm not entirely sure how does a power supply react to a laser, as I can't imagine the load being a particularly inductive one. but there's the transient response of the power supply to consider, its basically how fast the power supply can react to a sudden load. Linear or Switching relies an an error amplifier somewhere to maintain regulation. If the output load quickly changes from say full load to half load, the output voltage of the power supply will spike until the internal control circuit compensates for it and continues to compensate until the voltage dips from overcompensation. Then the reverse occurs. This brief delay may mean nothing for resistive loads, but if your load is sensitive to voltage spikes, go linear. For a 50% change in load a switcher may take 3000uS to recover while a linear supply will likely recover around 50uS.
Finally, since you mentioned you'll be doing experimentation. You would also have to keep current leakage across the Earth line in mind. In switchers there will be high voltage bipolar caps across the AC bus to Earth for reasons to dampen or eliminate feedback noise, but these caps do leak a tiny amount of current through Earth. If your oscilloscope uses Earth as the ground reference, you might get really bizarre readings.
Just a few things to think about. I'm sure someone who is actually been in the industry and not a hobbyist will chime in with better answers