Single Pixel Quadrature Imaging with Metamaterials

Compressed sensing in spectroscopy for chemical analysis

“…Table 1 Selected examples of imaging and spectroscopy techniques benefiting from compressed sensing X-ray diffraction 26,27 X-ray uorescence spectroscopy 28 Laser induced breakdown spectroscopy 29,30 Fluorescence spectroscopy [31][32][33][34][35][36] Bioluminescence spectroscopy 37 Raman spectroscopy [38][39][40][41][42][43] Infrared spectroscopy [44][45][46][47][48][49][50][51] Sum frequency generation spectroscopy 52,53 Terahertz spectroscopy [54][55][56][57] Multidimensional nuclear magnetic resonance 58,59 Magnetic resonance imaging [60][61][62][63][64][65][66] Electron microscopy [67][68][69][70][71] Electron energy loss spectroscopy 72,…”

Terahertz two-pixel imaging based on complementary compressive sensing

“…With the progress of reconstruction algorithms and the fabrication of masks, the application of CS imaging has extended from visible light and microwave to the THz region. Different THz-wave modulators such as copper-clad printed circuit boards, [4] metamaterials, [5] semiconductors, [6] and graphene [7,8] have been adopted. Due to its highly undersampled measurements, CS imaging can remedy the defect of prior imaging art in the THz range.…”

Metamaterial modulators enable new terahertz imaging techniques

“…Two distinct masks from the Hadamard matrix (mask 1 and mask 2) are encoded simultaneously by the SLM, and light is then refocused into a single-pixel detector. 4 The Q and I axes correspond respectively to the quadrature and in-phase components of the QPSK states. gap in current technology ranging from about 0.1 to 10 terahertz (THz), often referred to as the 'terahertz gap.'…”

“…5 Further, the measurement process remains serial, meaning that acquisition time is still directly proportional to the desired image size. 4,11 We developed an efficient single-pixel imaging system enabled by a metamaterial SLM 6 whose pixels' absorption peak can be dynamically brought high or low via applied bias voltage with great speed and precision. Light from a THz source passes through the object to be imaged and is focused onto the metamaterial SLM (see Figure 1).…”

“…=4; 3 =4; 5 =4; 7 =4/ instead of the original two, a method known as quadrature phase-shift keying (QPSK): see Figure 2(b). 4 With twice as many phase values, we can display two masks at once and simultaneously measure their results. This deterministically doubles the acquisition speed, since we complete the same number of measurements in half the time.…”