Please see source from 2009 LMT assessment below. They have updated their capabilities since then:
Appendix A. Laser Power Levels Required to Counter Targets
Table A-1 shows two Navy perspectives, a Defense Science Board (DSB) task force perspective, and two industry perspectives on approximate laser power levels needed to affect various categories of targets. As can be seen in the table, these perspectives differ somewhat regarding the power levels needed to counter certain targets, perhaps because of differing assumptions about beam quality (BQ) and other factors.
Table A-1.Approximate Laser Power Levels Needed to Affect Certain Targets
Multiple perspectives that may reflect varying assumptions about BQ and other factors
Source Beam power measured in kilowatts (kW) megawatts (MW)
~10 kW Tens of kW ~100 kW Hundreds of kW MW
One Navy briefing (2010)
UAVs
Small boats
Missiles (starting at 500 kW)
Another Navy briefing (2010) Short-range operations against UAVs, RAM, MANPADS (50 kW-100kW; low BQ) Extended-range operations against UAVs, RAM, MANPADS, ASCMs flying a crossing path (>100 kW, BQ of ~2)
Operations against supersonic, highly maneuverable ASCMs, transonic air-to-surface missiles, and ballistic missiles (>1 MW)
Industry briefing (2010) UAVs and small boats (50 kW) RAM (100+ kW), subsonic ASCMs (300 kW), manned aircraft (500 kW) Supersonic ASCMs and ballistic missiles Defense Science Board (DSB) report (2007) Surface threats at 1-2 km Ground-based air and missile defense, and countering rockets, artillery, and mortars, at 5- 10 kma “Battle group defense” at 5-20 km (1-3 MW)
Northrop Grumman research paper (2005) Soft UAVs at short range Aircraft and cruise missiles at short range Soft UAVs at long range Aircraft and cruise missiles at long range, and artillery rockets (lower hundreds of kW)
Artillery shells and terminal defense against very short range ballistic missiles (higher 100s of kW)
Source: One Navy briefing: Briefing slide entitled “HEL [High-Energy Laser] Missions,” in briefing entitled “Directed Energy Warfare Office (DEWO) Overview,” July 23, 2010.
Another Navy briefing: Briefing slide entitled “Surface Navy Laser Vision,” in briefing entitled “Navy Directed Energy Efforts – Ship Based Laser Weapon System,” July 23, 2010. Industry briefing: Briefing to CRS by an industry firm in the summer of 2010; data shown in table used here with the firm’s permission. DSB report: [Report of] Defense Science Board Task Force on Directed Energy Weapons, December 2007, Table 2 (page 12). Northrop Grumman research paper: Richard J. Dunn, III, Operational Implications of Laser Weapons, Northrop Grumman (Analysis Center Papers), September 2005 (available online at Analysis Center Paper on Lasers 2009 ), visual inspection of Figure 1 (page 7).