Determining the transfer function of a reconstructive spectrometer using measurements at two wavelengths

Area of Science:

• Optics and Photonics
• Spectroscopy
• Materials Science

Background:

• The transfer function characterizes a spectrometer's dispersive element, mapping spatial intensity to spectral intensity.
• Traditional methods require tunable, narrowband sources, increasing spectrometer development costs.
• Efficient characterization of dispersive elements is crucial for accurate spectral reconstruction.

Purpose of the Study:

• To develop a cost-effective method for determining the transfer function of reconstructive spectrometers.
• To utilize the unique properties of a photonic crystal cavity for simplified spectrometer calibration.
• To demonstrate reliable spectral reconstruction using the proposed method.

Main Methods:

• Employed a planar one-dimensional photonic crystal cavity as the dispersive element.
• Leveraged the parabolic dispersion relation of the cavity.
• Determined the spectrometer's transfer function using measurements at only two wavelengths.

Main Results:

• Successfully determined the entire transfer function with minimal spectral measurements.
• Demonstrated reliable input spectra reconstruction in simulations, robust to noise.
• Experimental results showed reconstructed spectra matching those from a commercial spectrometer.

Conclusions:

• The proposed method significantly reduces the complexity and cost of calibrating reconstructive spectrometers.
• Photonic crystal cavities offer an efficient solution for characterizing spectrometer dispersive elements.
• This approach enables accurate spectral reconstruction, paving the way for more accessible spectrometer technology.