Japan recently fired a 2 petawatt laser and believe this could be a pathway to commercial nuclear fusion.
Ultrapowerful lasers have been increasing in power by 1000 times every ten years for the past forty years.
Current technology is sufficient for the ten petawatt lasers.
The formulation for the glasses needed for exawatt lasers is known but there is currently no vendor.
Liquid cooling can enable one shot per minute or better. There are other laser types that have lower power but very high repetition rates. One of many goals is to increase the power and increase the repetition rate.
30 Petawatts once per second with 30kJ of energy should be enough for proton boron fuel commercial fusion
The researchers at the Japan LFEX 2 petawatt laser calculated that 30PW picosecond laser pulses with 30kJ energy irradiating a solid cylinder of HB11 fuel of centimeter length and millimeter radius in a 10 kilotesla magnetic field may produce more than 280kWh electric energy (worth about $28). The calculation assumed a spherical reactor of more than 1 meter radius around a central reaction unit that is charged to −1.4 million volts. This voltage stops the generated alpha particles and converts their kinetic energy into electric energy. A very small fraction of this energy is needed to drive the lasers, and we further estimated costs of about $18 per shot associated with replacing the HB11 fuel and the reaction unit (which is destroyed each time) and recharging it. At a rate of one reaction per second, the generated electricity would produce a net income of over $300 million/year.