Submersible light fixture with multilayer stack for pressure transfer

An underwater light, comprising:

• a housing comprising a thermally conductive material;
• a transparent pressure bearing window positioned at a forward end of the housing;
• a window supporting spacer mounted in the housing behind the transparent window;
• a water-tight seal between the window and the housing;
• a metal core printed circuit board (MCPCB), having a front side and a rear side, thermally coupled to the housing and configured and positioned within the housing behind the window supporting spacer so as to bear substantially all of the pressure applied to the transparent window by ambient water on an exterior side of the window when the housing and transparent pressure bearing window are subjected to deep ocean pressures;
• at least one solid state light source mounted on the front side of the MCPCB behind the transparent window;
• and
• a solid state light source spacer positioned between the front side of the MCPCB and the window supporting spacer, the spacer comprising an electrically non-conductive high compressive strength material and having one or more apertures shaped to fit around ones of the one or more solid state light sources to allow light to pass through;
• wherein the window supporting spacer includes one or more apertures shaped to fit around ones of the one or more solid state light sources to allow light to pass through, and wherein the housing, transparent pressure bearing window, window supporting spacer, MCPCB, solid state light source(s) and spacer are positioned so that loading from the ambient water applied to the forward facing side of the transparent pressure bearing window is carried substantially all through the transparent pressure bearing window to the window supporting spacer, and then from the window supporting spacer to the spacer, and then through the spacer to the front side of the MCPCB, and then through the rear side of the MCPCB to the housing.