text: TLE uses continuous-wave lasers (typically with a wavelength of around 1000 nm) located outside the vacuum chamber to heat sources of material in order to generate a flux of vapor via evaporation or sublimation. Owing to the localized nature of the heat induced by the laser, a portion of the source may be transformed into a liquid state while the rest remains solid, such that the source acts as its own crucible. The strong absorption of light causes the laser-induced heat to be highly localized via the small diameter of the laser beam, which can also have the effect of confining the heat to the axis of the source. The resulting absorption corresponds to a typical photon penetration depth on the order of 2 nm due to the high absorption coefficients of α ~ 10 cm of many materials. Heat loss via conduction and radiation further localizes the high-temperature region close to the irradiated surface of the source. The localized character of the heating enables many materials to be grown by TLE from freestanding sources without a crucible. Owing to the direct transfer of energy from the laser to the source, TLE is more efficient than other evaporation techniques such as  evaporation and molecular beam epitaxy, which typically rely on wire-based  Joule heaters to reach high temperatures.
  By heating the source, a flux of vapor is produced, the pressure of which frequently has an approximately exponential relation to temperature. The vapor is then deposited onto a substrate, which is heated via a laser. This laser-heated substrate allows the use of adsorption-controlled growth modes, similar to molecular beam epitaxy, ensuring precise control of the stoichiometry and temperature of the deposited film. This precise control is valuable for growing thin-film heterostructures of complex materials, such as  high-T superconductors. By positioning all lasers outside of the evaporation chamber, contamination can be reduced compared to using in situ heaters, resulting in highly pure deposited films.
  The deposition rate of the vapor impinging upon the substrate is controlled by adjusting the power of the incident source laser. The deposition rate frequently increases exponentially with source temperature, which in turn increases linearly with incident laser power.  
  The gas in the chamber can be incorporated in the deposition film. With the addition of an oxygen or ozone atmosphere, oxide films can readily be grown with TLE at pressures up to 10 hPa.