## 3 Results  
### SEM, EDX, and Confocal Analysis of \(\beta\)-TCP Discs  
Figure 2 shows SEM images before and after laser treatment with N = 1, 10, and 100 pulses and F = 0.8 J/cm\({}^{2}\). The selection of the representative morphological pictures acquired for laser irradiation with N = 1, 10, and 100 was done on the basis of monitoring distinct transitions in the process of laser ablation, which occurred after a certain change (an increase of N) of applied laser parameters--Table 1. This permits us to define concrete parametric conditions, from which the morphological changes on the surface and in the bulk of the material are triggered, as well as to separate material changes related to the frame interval of N = 1, N = 10, and N = 100. A clear difference in the morphological patterns of the \(\beta\)-TCP surfaces was noted after laser modification--the visible granular surface of the untreated \(\beta\)-TCP pellets (Control \(\beta\)-TCP- a group I) is replaced by gentle surface patterning, in the case of N = 1 (N = 1, F = 0.8 J/cm\({}^{2}\) group II), with the initiation of the first signs of material ejection. No grooves and cracks are observed for this type of processing condition. As we increase further the number of laser pulses to 10, grooves are formed on the surface with clear edges and without the onset of melted zones (N = 10, F = 0.8 J/cm\({}^{2}\) group III). In the case of N = 100 (group IV), severe laser modification of the sample is achieved and the ablation proceeds with the ejection of the ceramic material at the edges of the processed area. The formation of cracks around the crater boundary is monitored, which leads to disturbance of the \(\beta\)-TCP material integrity (Figure 2). Analogical laser patterning is established when F = 1.25 J/cm\({}^{2}\) and N = 5 \(\div\) 100 are applied (Figure 3). By increasing the number of pulses, the creation of grooves with subsequent formation of ripples and cracks is observed. The EDX spectra results presented in a table, showing the element concentration [wt.%] of \(\beta\)-TCP discs before and after laser treatment, are shown in Figure 2. The control \(\beta\)-TCP samples revealed the presence of oxygen (O), calcium (Ca), phosphorus (P), and carbon (C), which are commonly present chemical elements in the \(\beta\)-tricalcium phosphate (Ca\({}_{3}\)(PO\({}_{4}\))\({}_{2}\)). The data showed a reduced amount of Ca, P, and C elements and an elevated level of oxygen O by increasing the number of applied laser pulses (Figure 2 group I-IV). The only exception is at N = 100 (Figure 2 group IV), when O element concentration [wt.%] decreased and the Ca amount increased in relation to the control (untreated) \(\beta\)-TCP sample. This result could be attributed to the fact that, by applying a higher number of laser pulses, a subsequent increase of Ca-P bonds' fragmentation is observed owing to increased material ejection, triggered from the high-intensity femtosecond laser-matter interaction, thus confirming once again that optimizing laser parameters is crucial for such topography modifications. For both laser fluences (F = 0.8 J/cm\({}^{2}\) and F = 1.25 J/cm\({}^{2}\)), the formation of recasts along the boundaries of the processed channel for N = 100 is monitored. Moreover, the bottoms of the microchannels are characterized by the formation of dimple-like structures. The effect of the influence of a number of applied laser pulses on the width of produced microchannels in spot by spot regime demonstrated in Figure 3 is shown in the plot below (Figure 4). The increasing number of applied laser pulses influences the dimensions of microchannels in the low power regime more notably. It is observed that the boundary morphologies of the micro-channels are strongly affected by the influence of the increasing number of pulses, resulting in a micro-channel width increment. This increment shows a stable tendency for F = 1.25 J/cm\({}^{2}\) and for N, 5, 30, and 100.