High pulse energy diode array laser systems have been constructed for therapeutic and diagnostic medical applications. Two systems are described. One system, constructed for therapeutic application in dermatology, uses 45 bars to generate > 10 joules of energy at approximately 800 nm in a 5-millisecond pulse. This system uses simple microlenses and non- imaging condensers to uniformly illuminate areas of 0.1 to 0.4 cm2 at fluences up to 40 joules per cm2. Cooling, power, and control electronics are housed within the control console, and the laser and condensing optics are housed in the handpiece connected to the control console by means of a two-meter umbilical. The complete system, including closed- cycle cooling, weighs under 14 kg and uses < 2 amps at 110 V. A second system, which is being developed as a burn diagnostic, utilizes a 15-bar diode laser array. The array generates over 3 joules of optical energy. The output light is homogenized and projected using microlenses, a non-imaging condenser, and projection optics. With this system an area of approximately 1000 cm2 can be uniformly illuminated at an intensity of one millijoule per square centimeter. The system, including receiving optics, can be battery-powered and packaged into a hand-held unit.