Techniques described and illustrated herein can permit high
luminous flux and / or longer lifetimes for a class of photoemissive device configurations and / or uses that generate intense highly localized, but transient
heat flux. For example, certain
Light Emitting Diode (LED) applications, e.g., for flash illumination, certain
solid state
laser configurations and other similar configurations and uses may benefit from the developed techniques. In particular, it has been discovered that by locating an amount of appropriate
phase change material in close thermal proximity to such a photoemissive device, substantial generated heat fluxes may be “absorbed” into a
phase transition of the
phase change material. In some configurations, a thermoelectric is employed in conjunction with the
phase change material. For example, the thermoelectric may at least partially define a
heat transfer path from the photoemissive device to the
phase change material. Similar configurations may be employed for photosensitive devices. In such configurations, the
phase change material may effectively clamp one side (typically the hot side) of the thermoelectric as heat transferred across the thermoelectric is absorbed into the transition of at least some of the
phase change material from a first state thereof to a second state. The thermoelectric may be transiently operated in substantial synchrony with operation of the photoemissive or photosensitive device to provide extremely
high density spot cooling when and where desired.