A system comprising: a microscope (300a, 300b, 300c) having a first imaging modality and a Brillouin imaging modality (110, 110a, 110b, 110c); and a control unit operatively coupled to the first imaging and the Brillouin imaging modalities and configured to generate at least a spatially-resolved Brillouin measurement of a sample, wherein an acquisition speed of the first imaging modality is at least an order of magnitude faster than that of the Brillouin imaging modality, wherein the control unit is configured to: generate the spatially-resolved Brillouin measurement based on information generated by the first imaging modality, and unmix Brillouin signatures of different materials within a voxel (426, 608) of an interrogating beam of the Brillouin imaging modality based on the information generated by the first imaging modality, wherein the information generated by the first imaging modality comprises volume ratios for the different materials (422, 424, 602, 604, 606) within said voxel, wherein the voxel includes at least first and second different materials, and wherein the control unit is configured to: control the Brillouin imaging modality to acquire a first signature of the first material separate from the second material, control the first imaging modality to image the voxel and to determine the volume ratio of the first and second materials, and unmix the first signature from a signature of the voxel based on the determined volume ratio, so as to determine a second signature for the second material. a microscope (300a, 300b, 300c) having a first imaging modality and a Brillouin imaging modality (110, 110a, 110b, 110c); and a control unit operatively coupled to the first imaging and the Brillouin imaging modalities and configured to generate at least a spatially-resolved Brillouin measurement of a sample, wherein an acquisition speed of the first imaging modality is at least an order of magnitude faster than that of the Brillouin imaging modality, wherein the control unit is configured to: generate the spatially-resolved Brillouin measurement based on information generated by the first imaging modality, and unmix Brillouin signatures of different materials within a voxel (426, 608) of an interrogating beam of the Brillouin imaging modality based on the information generated by the first imaging modality, generate the spatially-resolved Brillouin measurement based on information generated by the first imaging modality, and unmix Brillouin signatures of different materials within a voxel (426, 608) of an interrogating beam of the Brillouin imaging modality based on the information generated by the first imaging modality, wherein the information generated by the first imaging modality comprises volume ratios for the different materials (422, 424, 602, 604, 606) within said voxel, wherein the voxel includes at least first and second different materials, and wherein the control unit is configured to: control the Brillouin imaging modality to acquire a first signature of the first material separate from the second material, control the first imaging modality to image the voxel and to determine the volume ratio of the first and second materials, and unmix the first signature from a signature of the voxel based on the determined volume ratio, so as to determine a second signature for the second material. control the Brillouin imaging modality to acquire a first signature of the first material separate from the second material, control the first imaging modality to image the voxel and to determine the volume ratio of the first and second materials, and unmix the first signature from a signature of the voxel based on the determined volume ratio, so as to determine a second signature for the second material.