Zona pellucida microdrilling with a 1.48 μm diode laser

The zona pellucida is the thick glycoprotein layer that surrounds and protects the female gamete. This layer plays an important part in mammalian reproduction. Here, the authors analyze a drilling process utilizing a 1.48 μm diode laser, and they review their mathematical model of the deposition of laser energy. They also present their results from experiments in which they drilled mouse zona pellucida. It is demonstrated that varying laser power or exposure duration controls the size of the hole. The authors observe that hole diameter is very sensitive to changes in exposure duration at the highest power used, due to a substantial increase in laser heating efficiency. At lower power settings, heat diffusion prevents efficient heating. Thus, deposition of the same amount of energy deposition results in a reduced hole size.