Fig. 1. The system schematic diagram. PM Source, polarization-modulated light source; BS, beam splitter; RM, reflective mirror; Ref. Plane, reference plane.

Fig. 2. The schematic diagram of the SPM module.

Fig. 3. The schematic diagram of the SPM-OCT system. SLD, super luminescent diode; PC, polarization controller; FC, fiber collimator; LP, linear polarizer; MP, multi-order wave plates; AP, achromatic quarter wave plate; BS, non-polarizing beam splitter; DC, dispersion compensator; ND, neutral density filter; RM, reference mirror; GV, galvanometer scanning mirror; SL, scanning lens; SP, spectrometer.

Fig. 4. (a) is the flowchart of the SPM-OCT imaging algorithm. (b) is the schematic diagram of the split-spectrum method.

Fig. 5. (a1) and (a2) are the modulation signals obtained in the χ domain under different angle conditions for QWP and LP, respectively. (b) shows the modulation signals of QWP and LP in the χ domain to the γ domain, respectively. (c1) is the validation result of retardation (δb) and optic axis (θb) values versus QWP orientation. (c2) is the validation result of the diattenuation ratio (δd) and transmission axis (θd) values versus LP orientation. (d1)–(d4) are δb, θb, δd, and θd B-scan images of the measured polarization elements at different angles. The scale bars in (d) are 1 mm.

Fig. 6. (a)–(c) are the intensity, intensity-retardation, and intensity-optic axis B-scan images of the skinned mouse leg, respectively. Labels 1 and 2 represent the images obtained by PS-OCT and SPM-OCT, respectively. Scale bars are 1 mm.

Fig. 7. (a)–(c) are the intensity, intensity-retardation, and intensity-optic axis en-face images of the skinned mouse leg, respectively. Labels 1 and 2 represent the images obtained by PS-OCT and SPM-OCT, respectively. The images of labels 3 and 4 are enlarged images of the areas selected by the dotted lines in the images of labels 1 and 2, respectively. Scale bars of images of labels 1 and 2 are 1 mm. Scale bars of images of labels 3 and 4 are 400 μm.

Fig. 8. (a)–(d) are the retardation, optic axis, diattenuation ratio, and transmission axis images of the sample, respectively. Labels 1 and 2 represent the skinned mouse leg and GNR phantom, respectively.

Fig. 9. Box plots of retardation and diattenuation of lipid, muscle, and GNR.