is not affected by most wavelengths that alter its light transmissivity or clarity the lens 50 is made from material having high light transmissivity such as for example only glass quartz high temperature and transparent plastic or a combination of these materials the lens 50 is placed on top of and adheres to the encapsulation material 46 the lens 50 is not rigidly bonded to the reflector 40 this u201c floating lens u201d design enables the encapsulant 46 to expand and contract under high and low temperature conditions without difficulty for instance when the die package 10 is operating or being subjected to a high temperature environment the encapsulant 46 experiences greater volumetric expansion than the cavity space that contains it by allowing the lens 50 to float up somewhat freely on top of the encapsulant 46 no encapsulant will be squeezed out of its cavity space likewise when the die package 10 is subjected to a cold temperature the encapsulant 46 will contract more than the other components that make up the cavity space for the encapsulant 46 the lens will float freely on top of the encapsulant 46 as the latter shrinks and its level drops hence the reliability of the die package 10 is maintained over relatively large temperature ranges as the thermal stresses induced on the encapsulant 46 is reduced by the floating lens design in some embodiments the lens 50 defines a recess 52 see fig3 having a.