## 3 Results
The field of view of the large images is 11 mm (x) and 867 μm (z). E (epithelium), B (Bowman’s layer), S (stroma), D ([PERSON]’s membrane), En (endothelium). Figure 2: Representative B-scan of the cornea recorded with the instrument in the co-polarized detection channel. (**a**) Without variable dispersion compensation (fixed parameter over the entire B-scan) dispersion is clearly visible at the periphery of the cornea; (**b**) B-scan evaluated with variable dispersion compensation. The lower row shows magnified views (3\(\times\)) of the regions of interest (1,2) that are marked with white rectangles in the upper row. White arrows point to artefacts at the corneal surface. Red arrows indicate the axial point spread function. Green arrows indicate a thickening of the topmost layer of the epithelium. The field of view of the large images is 11 mm (x) and 867 μm (z). The image retrieved from the cross-polarized channel shows different structures. The epithelium does not alter the polarization state of the light. Thus, only the surface of the cornea (due to the very strong signal from this layer and corresponding cross-talk into this polarization channel) can be observed. The interface between epithelium and [PERSON]'s layer, although clearly visible in the co-polarized channel, cannot be seen. A signal can be observed in this detection channel starting roughly at the center of [PERSON]'s layer and continues throughout the stroma. This originates from the depolarization of backscattered light that already originates at [PERSON]'s layer. The stroma shows very fine structures in the anterior part that evolve into larger patterns with depth. This gradual change may be associated with the varying collagen density within the stroma. Interestingly, [PERSON]'s membrane appears very dark in the image indicating that almost no light returning from this layer is in a cross polarized state. Thus, this layer can be well separated from other corneal layers and corresponding layer segmentation may be facilitated by the usage of these images. Another interesting detail is the observation of only a single layer at the endothelium. The double layer structure can only be observed in the image retrieved from the co-polarized channel. It is highlighted here that the double layer is not an artifact caused by side lobes of the coherence function as these appear symmetrically around the main peak and have lower signal strength. The combined image of both channels (total intensity) shows lower contrast of all features presented above. In order to better visualize the signal behavior with the depth in the two polarization channels, an average (mean) of the central 100 A-scans of the images displayed in Figure 3 was plotted. As can be seen in Figure 4, the individual corneal interfaces are clearly visible in the data of the co-polarized detection channel (black curve). The data of the cross polarized detection channel reveals an increase of signal intensity starting at the interface between the epithelium and Bowman's layer that reaches a maximum at the interface between [PERSON]'s layer and the stroma. In a next step, 3-dimensional image data were recorded and the depth varying structure of the stroma that is visible in the images of the cross polarized channel was investigated. Figure 5 shows the representative image data. The en-face images retrieved at different imaging depths clearly show that the fine structures that are observed in the anterior part of the stroma evolve into larger connected patterns in deeper regions of the cornea. Figure 4: Averaged depth profiles of the central 100 A-scans of the images displayed in Figure 3. Black indicates the co-polarized, red the cross-polarized detection channel. The arrows point to the different corneal interfaces. E (epithelium), B ([PERSON]’s layer), S (stroma), D (Descemet’s membrane), En (endothelium).