Peak Power Characterization of Ultrashort Optical Pulses

<p dir="ltr">Ultrashort optical pulses have extremely high peak powers, making them useful for research in nonlinear optics, biomedical imaging, and micromachining. However, directly measuring peak power is challenging due to its short pulse duration. This research focuses on evaluating and comparing three nonlinear optical methods for estimating the peak power of femtosecond laser pulses: second harmonic generation (SHG), two-photon absorption (TPA), and nonlinear spectral broadening. SHG was measured using a BBO crystal, while TPA was measured via photocurrent in a silicon photodiode. Spectral broadening was analyzed using a nonlinear Schrödinger equation (NLSE) model in MATLAB and compared to experimental measurements through a 13-meter metrocor fiber. Initial results qualitatively confirm the correlation between peak power and each nonlinear effect, with future work focused on extracting quantitative peak power values and comparing the accuracy of each method.</p>