A mid-infrared high-performance spectropolarimetry filter based on dual-mode independent modulation

Area of Science:

• Optics and Photonics
• Biomedical Engineering
• Materials Science

Background:

• Spectropolarimetry offers valuable multi-dimensional data for applications in biomedicine and remote sensing.
• Current spectropolarimetry techniques face limitations, including bulky systems or miniaturized devices with insufficient spectral resolution and polarization selectivity, leading to information cross-talk.

Purpose of the Study:

• To propose and demonstrate a compact, single-chip integrated high-performance mid-infrared spectropolarimetry filter (SPF).
• To achieve independent modulation of spectral and polarization characteristics with high resolution and selectivity.

Main Methods:

• Design and fabrication of a novel spectropolarimetry filter (SPF) on a single chip.
• Independent modulation of narrowband spectral and polarization characteristics using different polarization modes.
• Characterization of the SPF's polarization extinction ratio (ER), spectral resolution (SR), and transmission efficiency in the mid-infrared band.

Main Results:

• The designed SPF exhibits a theoretical polarization extinction ratio (ER) over 10^6 and spectral resolution (SR) up to 822 with 90% transmission.
• Experimental results show an ER exceeding 3 × 10^4 and SR up to 387 with 60% transmission efficiency.
• The device successfully distinguished between striated muscle and rhabdomyosarcoma tissue in tumor diagnostics.

Conclusions:

• The developed compact SPF accurately obtains simultaneous spectral and polarization information, overcoming limitations of existing methods.
• The device demonstrates potential for various applications, including advanced target detection and identification.
• The technology is adaptable to different wavelength ranges, offering a powerful new approach for multi-dimensional optical information acquisition.