Fiber & Lasers
Mode Field Diameter (MFD)
Marcuse approximation of the mode field diameter 2w of a step-index fiber.
w/a ≈ 0.65 + 1.6/V^1.5 + 2.8/V^6
Fill the inputs from a real part
Every number is read from that part's datasheet entry: peak power and pulse energy as rated, pulse width at the part's rated maximum.
Solve for
Inputs
Result
Live diagram
Drawn from the values above, redrawn as you type - the same physical schematic the mini-program shows.