Mostly the very youngest pulsars
Just 3 pulsars detected at Optical Wavelengths
Crab, Vela, B0540-69
X-ray - 27 detected, 13 pulsed
Gamma ray - 6 detected all pulsed
Radio emission 
of spin down energy
Opt,X, 
account for few %
Learn much more about magnetosphere etc
Mostly double peaked profiles from wide cones
Need radio ephemeris
18000 pulse periods elapse between each EGRET photon detected from the
Crab pulsar