Feasibility evaluation of transtympanic laser stimulation of the cochlea from the outer ear

Infrared laser stimulation has been studied as an alternative approach to auditory prostheses. This study evaluated the feasibility of infrared laser stimulation of the cochlea from the outer ear bypassing the middle ear function. An optic fiber was inserted into the ear canal and a laser was used to irradiate the cochlea through the tympanic membrane in Mongolian gerbil. A pulsed infrared laser (10.1 mJ/cm2) and clicking sound (70 peak-to-peak equivalent sound pressure level) were presented to the animals. The amplitude of the laser-evoked cochlear response was systematically decreased following insertion of a filter between the tympanic membrane and cochlea; however, the auditory-evoked cochlear response did not decrease. The filter was removed and the laser-evoked response returned to around the original level. The amplitude ratio and the relative change in response amplitude before and during filter insertion significantly decreased as the absorbance of the infrared filter increased. These results indicate that laser irradiation could bypass the function of the middle ear and directly activate the cochlea. Therefore, an auditory prosthesis based on laser stimulation represents a possible noninvasive alternative to conventional auditory prostheses requiring surgical implants.

Quantitative Study of Photoelectric Laser Stimulation for Logic State Imaging in Embedded SRAM

The use of optical techniques for attacking integrated circuits (ICs) at the silicon level is increasingly being reported. Although these attacks can be complex to set and require skilled attacker that can access expensive equipment, they are nonetheless very powerful. Among the different applications described in literature, there has been a focus on extracting data directly from embedded SRAM. Such attacks can provide access to highly sensitive information such as encryption keys and bypass various security strategies. An attacker usually exploits one of the several interactions that exist between light and semiconductor to generate an image where content can be directly qualified by the data in memory (Logic State Image – LSI). Thermal laser stimulation (TLS) and laser probing (EOFM-Electro-Optical Frequency Mapping) have been reported in the literature recently but Photoelectric Laser Stimulation (PLS) did not get as much attention. Considering the potential advantages of PLS over other techniques (e.g. lower power requirements to generate current/voltage change, effect can be triggered at shorter wavelength which may lead to an improved spatial resolution), we investigate in this paper if logic state images can be generated with PLS on a variety of devices and do a comparative assessment with state-of-the-art technologies to assess potential benefits and limitations.

The Use of Coherent Laser Stimulation of Seeds and a Fungal Inoculum to Increase the Productivity and Health of Soybean Plants

The laser stimulation of seeds is regarded as a modern method of seed enhancement. Our study evaluated the productivity and health of soybean plants resulting from the coherent irradiation of seeds and irradiation of an arbuscular mycorrhizal fungi (AMF) inoculum. The two-factor pot experiment took into account (1) the type of irradiated biological material (seeds, AMF inoculum, and seeds and inoculum) and (2) the means of irradiation (red laser—LR, blue laser—LB, red and blue laser—LR + LB, and control). Seed weight per plant, pod number per plant, root weight, the Fv/Fm fluorescence parameters, and the health status of the aboveground and underground parts of the plants were assessed. Stimulation with a laser light was shown to have a positive effect on the productivity and health of soybean plants. Significantly better effects can be obtained by stimulating the seeds alone. The stimulation of seeds treated with AMF inoculum slightly reduced the productivity of the plants. However, with regards to the conditions of plants, the treatment of seeds with AMF inoculum and laser irradiation was shown to reduce the incidence of Septoria brown spots.