J Opt Soc Am A Opt Image Sci Vis. 2022 Jan 1;39(1):127-135. doi: 10.1364/JOSAA.441684.
Daylight photodynamic therapy (D-PDT) is an effective and almost painless treatment for many skin conditions, where successful treatment relies on daylight activation of a topical photosensitizer. Optimization of D-PDT requires accurate assessment of light dose received. There is a requirement for a small-area sensor that can be placed adjacent to the treatment site to facilitate accurate dose quantification. Here, a novel, to the best of our knowledge, configuration for a D-PDT dose sensor, consisting of a holographic absorption grating fabricated in a photosensitive film, is presented. Theoretical modeling of the sensor's response (i.e., change in grating diffraction efficiency due to change in grating absorption modulation, , on exposure to daylight) was conducted using Kogelnik's coupled-wave theory. The influence of the different grating parameters (initial film absorption, thickness, spatial frequency, and reconstruction wavelength) on the sensor response was examined and revealed that the initial absorption and grating thickness values have a large impact on both the magnitude and rate of the D-PDT sensor response. The optimum design for an absorption grating-based D-PDT sensor is described.
日光光动力疗法（D-PDT）是一种有效且几乎无痛的治疗许多皮肤疾病的方法，成功的治疗依赖于日光对局部光敏剂的激活。D-PDT 的优化需要准确评估所接受的光剂量。需要一种小面积传感器，可放置在治疗部位附近，以方便准确的剂量量化。在这里，提出了一种新颖的、据我们所知的 D-PDT 剂量传感器配置，由光敏膜中的全息吸收光栅组成。使用 Kogelnik 的耦合波理论对传感器的响应（即，由于光栅吸收调制的变化，即，在暴露于日光下时，光栅衍射效率的变化）进行了理论建模。研究了不同光栅参数（初始膜吸收、厚度、空间频率和重建波长）对传感器响应的影响，结果表明初始吸收和光栅厚度值对 D-PDT 传感器响应的幅度和速率有很大影响。描述了基于吸收光栅的 D-PDT 传感器的最佳设计。
