Dataset for: Quantitative Optical–Electrical Proportionality Between Bragg Wavelength Shift and Photovoltaic Voltage Variation

This dataset contains synchronized measurements of Bragg wavelength shift, reference temperature, and photovoltaic voltage recorded at 1 Hz during controlled thermal cycling (48.3–77.7 °C heating and 77.7–37.2 °C cooling). The data support regression and proportionality analysis between optical wavelength variation and photovoltaic voltage behavior presented in the associated manuscript.