Cooling disk lasers

A laser disk module comprising:

• a lasing element including an active gain medium, the lasing element including opposite top and bottom end surfaces;
• and
• a heat transfer element adjacent the bottom end surface, the heat transfer element including a ceramic material that defines a plurality of cooling structures,
• wherein the heat transfer element is configured to transfer heat generated in the lasing element to a coolant in contact with the heat transfer element in the plurality of cooling structures during operation of the laser disk module,
• wherein the heat transfer element includes a plurality of layers that forms the plurality of cooling structures when the layers are joint together,
• wherein the plurality of layers includes:
• a first layer adjacent the back end face of the lasing element, the first layer being a solid plate;
• and
• a second layer adjacent the first layer, the second layer including a plurality of second channels that is radially distributed between a center of the second layer and a peripheral edge of the second layer,
• wherein the plurality of layers further includes:
• a third layer adjacent the second layer, the third layer including a plurality of third channels that is radially distributed between a center of the third layer to a peripheral edge of the third layer, the third channels crossing over the second channels and being configured to permit the coolant to flow freely between the second channels and the third channels during the operation of the laser disk module,
• wherein each channel of the second channels has a first arrow shape defining a first acute angle pointing to the center of the second layer, and each channel of the third channels has a second arrow shape defining a second acute angle pointing to the peripheral edge of the third layer, and
• wherein the centers of the first, second and third layers are coaxial and the first, second and third layers have a substantially same diameter.

A thin disk laser module comprising:

• a thin crystal disk of active gain medium, the thin crystal disk including opposite top and bottom end surfaces that define a thickness therebetween along a longitudinal direction substantially perpendicular to the bottom end surface;
• and
• a heat transfer element adjacent the thin crystal disk along the longitudinal direction, the heat transfer element being made of a ceramic material, the heat transfer element including:
• a heat transfer front side coupled to the bottom end surface of the thin crystal disk, the heat transfer front side including a solid plate;
• and
• a heat transfer back side including a plurality of cooling structures that are open to a bottom surface of the heat transfer front side along the longitudinal direction,
• wherein the heat transfer element is configured to transfer heat generated in the thin crystal disk to a cooling fluid in a direct contact with the bottom surface of the heat transfer front side and with the heat transfer back side in the plurality of cooling structures during operation of the thin disk laser module, and
• wherein the plurality of cooling structures is radially distributed between a center of the heat transfer element and a peripheral edge of the heat transfer element, the cooling structures including a plurality of solid parts that defines a plurality of channels, each of the solid parts having a rhombus shape defining an acute angle.