A portable thermal imaging system comprising: a portable housing configured to be carried by a user; a bolometer sensor assembly supported by the housing and including an array of thermal sensor elements (854 1-5), wherein the bolometer sensor assembly comprises a substrate (104; 304; 404; 504; 604; 704; 850) having an upper surface supporting the array of thermal sensor elements (854 1-5); a memory including program instructions; and a processor operably connected to the memory and to the bolometer sensor assembly, and configured to execute the program instructions to obtain signals from each of a selected set of thermal sensor elements (854 1-5) of the array of thermal sensor elements (854 1-5) assign each of the obtained signals with a respective color data associated with a temperature of a sensed object, and render the color data; characterized in that the bolometer sensor assembly further comprises: a cap wafer (112; 312; 412; 512; 612; 712; 858) formed from a first material and supported by the substrate (104; 304; 404; 504; 604; 704; 850) and including a support structure extending from an upper surface of the substrate (104; 304; 404; 504; 604; 704; 850) and a cap layer extending from the support structure and being spaced apart from the substrate (104; 304; 404; 504; 604; 704; 850) such that a cavity is defined between the upper surface of the substrate (104; 304; 404; 504; 604; 704; 850) and a lower surface of the cap layer, wherein a lens layer (114; 314; 514; 614; 714) is supported on an upper surface of the cap layer, wherein the lens layer (114; 314; 514; 614; 714) includes at least one plasmonic lens (116; 316; 416; 516; 616; 716; 860), and wherein ridges are formed on the cap layer; wherein the at least one plasmonic lens (116; 316; 416; 516; 616; 716; 860) comprises a plurality of grooves in the lens layer (114; 314; 514; 614; 714), wherein the grooves are complementary in shape and size to the ridges formed on the cap layer such that the grooves are at least partially filled by the ridges made of the first material; and wherein the first material is silicon and the lens layer (114; 314; 514; 614; 714) is formed of a metal material. a portable housing configured to be carried by a user; a bolometer sensor assembly supported by the housing and including an array of thermal sensor elements (854 1-5), wherein the bolometer sensor assembly comprises a substrate (104; 304; 404; 504; 604; 704; 850) having an upper surface supporting the array of thermal sensor elements (854 1-5); a memory including program instructions; and a processor operably connected to the memory and to the bolometer sensor assembly, and configured to execute the program instructions to obtain signals from each of a selected set of thermal sensor elements (854 1-5) of the array of thermal sensor elements (854 1-5) assign each of the obtained signals with a respective color data associated with a temperature of a sensed object, and render the color data; characterized in that the bolometer sensor assembly further comprises: obtain signals from each of a selected set of thermal sensor elements (854 1-5) of the array of thermal sensor elements (854 1-5) assign each of the obtained signals with a respective color data associated with a temperature of a sensed object, and render the color data; characterized in that the bolometer sensor assembly further comprises: a cap wafer (112; 312; 412; 512; 612; 712; 858) formed from a first material and supported by the substrate (104; 304; 404; 504; 604; 704; 850) and including a support structure extending from an upper surface of the substrate (104; 304; 404; 504; 604; 704; 850) and a cap layer extending from the support structure and being spaced apart from the substrate (104; 304; 404; 504; 604; 704; 850) such that a cavity is defined between the upper surface of the substrate (104; 304; 404; 504; 604; 704; 850) and a lower surface of the cap layer, wherein a lens layer (114; 314; 514; 614; 714) is supported on an upper surface of the cap layer, wherein the lens layer (114; 314; 514; 614; 714) includes at least one plasmonic lens (116; 316; 416; 516; 616; 716; 860), and wherein ridges are formed on the cap layer; wherein the at least one plasmonic lens (116; 316; 416; 516; 616; 716; 860) comprises a plurality of grooves in the lens layer (114; 314; 514; 614; 714), wherein the grooves are complementary in shape and size to the ridges formed on the cap layer such that the grooves are at least partially filled by the ridges made of the first material; and wherein the first material is silicon and the lens layer (114; 314; 514; 614; 714) is formed of a metal material.