High-precision temperature measurement based on weak measurement using nematic liquid crystals

Abstract

High-precision temperature measurements could guarantee temperature difference control accuracy in research and industrial production. To flexibly achieve high precision and large operating temperature range is a crucial problem for temperature measurements. Here, we demonstrate a method for a high-precision temperature measurement based on a weak measurement done using nematic liquid crystals (NLCs). By performing an analysis in the frequency domain, the temperature variation of NLCs is measured using a Sagnac interferometer with appropriate preselection and postselection. In order to obtain a large operating temperature range, there is a relatively large time delay that resulted from NLCs, and an operational principle is deduced explicitly by Jones matrices. In the proposed method, the precision of 3 × 10−6 °C could be achieved by a currently available spectrometer and the operating temperature range can be modulated by the thickness of NLCs. Moreover, the temperature sensitivity of 13.5 nm/°C could be realized for NLCs with 100 μm thickness, which exhibits at least three orders of magnitude larger than the value for other frequency domain analyses.

Toward ultrahigh sensitivity in weak-value amplification

“…More examples could be found in the applications on measuring other parameters with high sensitivities, e.g. velocity@400fm/s [13], non-linearity@singlephoton level [14], temperature@3 × 10 −6o C [15,16], optical rotation@1.88 × 10 −5o [17], time-domain longitudinal phase change@sub-attosecond level [18,19], etc. These applications employ the standard WVA approach, in which only a tiny portion of the signal surviving post-selection are collected and measured [20].…”

Universality of local weak interactions and its application for interferometric alignment

“…Because of the linear relation between θy and px as well as θx and py, one obtains [32] δ θx = δ θx Re[(PA) w ], [33] δ y = −zRδ θx Im[(PA) w ]. [34] Here we have used the Rayleigh range zR ≡ πw 2 0 λ as the characteristic parameter of the Gaussian beam.…”

“…The concept of weak values became the basis of several successful applications in precision measurement techniques (7,8). While there are theoretical controversies about the optimality of the weak value-based tomography and precision-measurement methods (9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20) a plethora of fruitful applications continues to emerge (21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31)(32)(33)(34).…”

Robustness of optic-fiber-based weak-value amplification against amplitude-type noise

“…Three decades after the concept had been proposed, weak value amplification (WVA) [1] has recently become a useful technique for optical metrology [2][3][4][5][6][7]. Taking the advantage of suppressing certain kinds of technical noises and practical imperfections [8], WVA can efficiently improve the signal-to-noise ratio in practice, therefore provide higher sensitivity comparing to the standard techniques [9][10][11].…”