The use of photosensitive materials for the development of integrated, refractive-index structures supporting telecom, remote sensing, and varied optical beam manipulation applications is well established. Our investigations of photosensitive phenomena in polysilanes, however, have been motivated by the desire to configure, or program, the photonic device function immediately prior to use. Such an operational mode imposes requirements on wavelength sensitivity, incident fluence and environmental conditions that are not typical of more conventional applications of photosensitive material. The present paper focuses on our efforts to understand and manipulate photosensitivity in polysilane thin films under different excitation wavelengths, local atmospheric compositions and thermal history in this context. We find that the photoresponse can be influenced through the control of such optical exposure conditions, thereby influencing the magnitude of the photoinduced refractive-index change attained.