A high power laser drilling system for use in association with a drilling rig, drilling platform, drilling derrick, a snubbing platform, or coiled tubing drilling rig for advancing a borehole in hard rock, the system comprising: a. a source of high power laser energy, the laser source capable of providing a laser beam having at least 20 kW of power; b. a bottom hole assembly; i. the bottom hole assembly having an optical assembly; ii. the optical assembly comprising a beam power deposition optic having a property of modifying an energy deposition profile within the laser beam, and configured to provide a predetermined energy deposition profile to a borehole surface; wherein the modified energy deposition profile within the laser beam is different from the predetermined energy deposition profile provided to the borehole surface; and wherein the predetermined energy deposition profile provided to the borehole surface is a substantially even energy deposition profile on the borehole surface; and, iii. the optical assembly configured to provide a predetermined laser shot pattern; c. a means for advancing the bottom hole assembly into and down the borehole; d. a downhole high power laser transmission cable, the transmission cable having a length of at least about 0.3 km (1000 feet); e. the downhole cable in optical communication with the laser source; and, f. the downhole cable in optical communication with the bottom hole assembly. a. a source of high power laser energy, the laser source capable of providing a laser beam having at least 20 kW of power; b. a bottom hole assembly; i. the bottom hole assembly having an optical assembly; ii. the optical assembly comprising a beam power deposition optic having a property of modifying an energy deposition profile within the laser beam, and configured to provide a predetermined energy deposition profile to a borehole surface; wherein the modified energy deposition profile within the laser beam is different from the predetermined energy deposition profile provided to the borehole surface; and wherein the predetermined energy deposition profile provided to the borehole surface is a substantially even energy deposition profile on the borehole surface; and, iii. the optical assembly configured to provide a predetermined laser shot pattern; i. the bottom hole assembly having an optical assembly; ii. the optical assembly comprising a beam power deposition optic having a property of modifying an energy deposition profile within the laser beam, and configured to provide a predetermined energy deposition profile to a borehole surface; wherein the modified energy deposition profile within the laser beam is different from the predetermined energy deposition profile provided to the borehole surface; and wherein the predetermined energy deposition profile provided to the borehole surface is a substantially even energy deposition profile on the borehole surface; and, iii. the optical assembly configured to provide a predetermined laser shot pattern; c. a means for advancing the bottom hole assembly into and down the borehole; d. a downhole high power laser transmission cable, the transmission cable having a length of at least about 0.3 km (1000 feet); e. the downhole cable in optical communication with the laser source; and, f. the downhole cable in optical communication with the bottom hole assembly.