The present invention relates to a cryogenic cooler's expander supported by a support member, preferably a truncated conical tube. The support member provides additional stiffness to the expander to reduce movements at the distal end of the expander. The support member also increases the natural frequency of the expander. In one embodiment, the support member increases the natural frequency of the expander at least about two (2) times in the bending and/or twisting sense. In another embodiment, the bending natural frequency of the expander and support sub-assembly is at least about two times greater or lower than the natural frequency of the electrical wires that connect the infrared sensor to a control processing unit to reduce the maximum stress applied to the electrical wires during use. In another embodiment, additional or redundant electrical pathways are provided for the connection between the infrared sensor and the CPU. Furthermore, shock absorber and/or shock diverters are provided on the rigid pins that connect the electrical wires to the CPU.