We know that when mixing red with green that the sum of the power appears less than the individual powers of the lasers, but what happens when we mix two wavelengths of red?
In other words; I am building a multi red combiner, initially with 800mW of 637 and until funds allow, I was going to fill the remaining slots with 2W of 660; will the darker 660 drag down the 'apparent' brightness of the beam?