Simultaneous stimulated Raman gain and loss detection (SRGAL)

Abstract

The fidelity of stimulated Raman scattering (SRS) microscopy images is impaired by artifacts such as thermal lensing, cross-phase modulation and multi-photon absorption. These artifacts affect differently the stimulated Raman loss (SRL) and stimulated Raman gain (SRG) channels making SRL and SRG image comparisons attractive to identify and correct SRS image artifacts. To provide answer to the question: "Can I trust my SRS images?", we designed a novel, but straightforward SRS scheme that enables the dectection of the stimulated Raman gain and loss (SRGAL) simultaneously at the same pixel level. As an advantage over the conventional SRS imaging scheme, SRGAL doubles the SRS signal by acquiring both SRL as well as SRG and allows for the identification of SRS artifacts and their reduction via a balanced summation of the SRL and SRG images.

Multi-color stimulated Raman scattering with a frame-to-frame wavelength-tunable fiber-based light source

“…3(a)). In the labeled image area the SNR was between 14.2 (no averaging) and 29.2 (five averages), and thus in a comparable magnitude to other SRS experiments [40].…”

Practical considerations for quantitative and reproducible measurements with stimulated Raman scattering microscopy

“…While SRS becomes more widely employed, new challenges and technology developments are continuously being proposed; 72 such as simultaneous stimulated Raman gain and loss detection for eliminating the need for a separate off-resonance image. 73 Other important technologies include broadband CRS to enable faster data collection. 74 Challenges yet to be solved include much needed improvements in sensitivity, faster detectors with lower noise, and more stable laser sources.…”

Coherent Stokes Raman scattering microscopy (CSRS)

“…For example, pre-resonant CSRS will offer complementary information in application to alkyne-labeled dyes [12] and standard dyes used in microbiology [13]. (2) The red-shifted radiation of CSRS imaging becomes an advantage for UV or near-UV excitation where CARS photons [14] would be too far blue-shifted to be detected efficiently while any SRS image [15] is likely to be compromised by various artifacts such as multi-photon absorption [16,17]. Thus, UV excited CSRS holds the potential to achieve the highest possible spatial resolution (𝜆 Stokes /[ √ 8𝑁 𝐴]) in coherent Raman imaging.…”