An apparatus for detecting photothermal radiation and/or luminescence from an object, said apparatus comprising: an elongate housing comprising a handheld proximal body portion connected to a thermally conductive distal tip portion; a laser for producing a laser beam within said housing, wherein said laser beam comprises a wavelength suitable for generating luminescence radiation within said object; a focusing element positioned to focus said laser beam through an aperture within said distal tip portion of said housing and onto a surface of said object, and to collect photothermal radiation generated within said object in response to said laser beam, wherein said focusing element is configured to collect said luminescence radiation in addition to said photothermal radiation; and a dichroic beamsplitter positioned within said housing to spatially separate said photothermal radiation from said laser beam; and an infrared detector provided within said housing for detecting said photothermal radiation; an optical sampling element provided within said housing, wherein said optical sampling element is positioned to redirect sampled luminescence radiation; an optical filter positioned to transmit said sampled luminescence radiation and to reject scattered laser power; and a photodetector positioned to detect said sampled luminescence radiation; wherein at least said laser, said dichroic beamsplitter and said infrared detector are mounted on a thermally conductive optical bench; and wherein said thermally conductive optical bench is housed within said proximal body portion and attached to a proximal end of said thermally conductive distal tip portion, such that said optical bench is supported within said body portion by said distal tip portion, and such that said distal tip portion provides a heat sink for heat generated by optical components attached to said optical bench. an elongate housing comprising a handheld proximal body portion connected to a thermally conductive distal tip portion; a laser for producing a laser beam within said housing, wherein said laser beam comprises a wavelength suitable for generating luminescence radiation within said object; a focusing element positioned to focus said laser beam through an aperture within said distal tip portion of said housing and onto a surface of said object, and to collect photothermal radiation generated within said object in response to said laser beam, wherein said focusing element is configured to collect said luminescence radiation in addition to said photothermal radiation; and a dichroic beamsplitter positioned within said housing to spatially separate said photothermal radiation from said laser beam; and an infrared detector provided within said housing for detecting said photothermal radiation; an optical sampling element provided within said housing, wherein said optical sampling element is positioned to redirect sampled luminescence radiation; an optical filter positioned to transmit said sampled luminescence radiation and to reject scattered laser power; and a photodetector positioned to detect said sampled luminescence radiation; wherein at least said laser, said dichroic beamsplitter and said infrared detector are mounted on a thermally conductive optical bench; and wherein said thermally conductive optical bench is housed within said proximal body portion and attached to a proximal end of said thermally conductive distal tip portion, such that said optical bench is supported within said body portion by said distal tip portion, and such that said distal tip portion provides a heat sink for heat generated by optical components attached to said optical bench.