High rate modulation of laser diodes
I don't know any IC that can drive such a high power laser at that rate.

If this is for a bench-top test, you should be able to build a driver with a power amplifier, a current source, and a bias tee.







simulate this circuit &ndash; Schematic created using CircuitLab

The power amplifier should be wideband, from maybe 1 to 1000 MHz, and it will need to deliver at least 4 W to generate 400 mA modulation amplitidue (800 mA peak-peak). Maybe consider Minicircuits ZFL-1000, for example. 

Depending on the laser input impedance you might also need to add a series resistor in front of it for impedance matching. This resistor could be absorbing 80% of the input power, so you might have to trade off rf performance, resistor power rating, and impedance matching.

The current source should include compliance voltage limit in case of reverse connection, and you might also want a slow-start feature (although it's not likely to be needed on such a high-power laser).

The bias tee could be maybe Mini Circuits ZFBT-4R2GW+, although that has a max current of 500 mA so there's no margin from your requirement. 

You'll find that as you increase the extinction ratio, the jitter performance will become very bad. So yo won't ever achieve "full modulation". You'll have to experiment with bias current and modulation amplitude to find a good trade-off between modulation and jitter.