Controlled light field concentration through turbid biological membrane for phototherapy

Abstract

Laser propagation through a turbid rat dura mater membrane is shown to be controllable with a wavefront modulation technique. The scattered light field can be refocused into a target area behind the rat dura mater membrane with a 110 times intensity enhancement using a spatial light modulator. The efficient laser intensity concentration system is demonstrated to imitate the phototherapy for human brain tumors. The power density in the target area is enhanced more than 200 times compared with the input power density on the dura mater membrane, thus allowing continued irradiation concentration to the deep lesion without damage to the dura mater. Multibeam inputs along different directions, or at different positions, can be guided to focus to the same spot behind the membrane, hence providing a similar gamma knife function in optical spectral range. Moreover, both the polarization and the phase of the input field can be recovered in the target area, allowing coherent field superposition in comparison with the linear intensity superposition for the gamma knife.

Exploiting the point spread function for optical imaging through a scattering medium based on deconvolution method

“…With the development of technology, people got to¯nd methods to overcome this problem in the recent decade. 3 The most widespread reported techniques are wavefront shaping, [4][5][6][7] time-of-°ight imaging, 8,9 time reversal or phase conjugation, [10][11][12][13][14][15][16] transmission matrix measurement, [17][18][19][20] holography, [21][22][23] speckle correlation, [24][25][26][27][28][29][30][31][32][33][34][35] and so on. Among them, speckle correlation is thought to be a promising solution because it usually does not need coherent light sources, expensive wavefront modulators, complicated interference setups, nor a timeconsuming calibration.…”

Modeling of an optoelectronic system for data coding using orbital angular momentum of light

“…Twisted nematic spatial light modulators (TNSLMs) are optoelectronic pixilated devices that can be employed to modulate amplitude, phase or polarization of light beams in space and time [1]. Such devices are based on liquid crystal displays and they provide us novel tools to manipulate orbital angular momentum (OAM) of light in the fields of communications [2 a 4], medicine [5,6], biology [7,8] and holography [9,10]. To obtain an accurate control of the amplitude of the incident wavefront on a TNSLM and improve the experimental results obtained through them, it is important a proper calibration of the modulation response of a TNSLM.…”

Optical clearing of human dura mater by glucose solutions

“…The reduction of scattering would also decrease the divergence and provide better light beam focusing in cerebral surgery, which could essentially improve the efficiency of diagnostic procedures and reduce the energy of radiation, necessary for providing the required light effect [12,13].…”