In this paper, we overview some configurations of photonic devices for measuring mechanical strain and wavelength shift without use of spectrometer, which have been developed recently and demonstrated large potential application in sensing technique with low cost. There are three kinds of photonic sensor configurations to be presented: i) first of them is a fiber Bragg grating (FBG) for the measurement of mechanical dynamic strain of very small value using signal modulation on laser diode by composition of two wavelengths in the laser cavity; ii) second configuration is a FBG combined with a DFB laser diode whose emission wavelength controlled by laser temperature, and iii) last one uses a fiber ring laser from Erbium doped fiber and two FBG operated as reference and sensing probe. | Communications in Physics, Vol. 28, No. 2 (2018), pp. 139-153 DOI: WAVELENGTH SHIFT MEASUREMENT METHOD WITHOUT SPECTROMETER: THE NEW WAY FOR ENVIRONMENT PHOTONIC SENSORS PHAM VAN HOIa,b† , NGUYEN THUY VANa,b , PHAM VAN DAIa , BUI HUYa,b , LE HUU THANGb,c , NGUYEN VAN ANb,d AND PHAM THANH BINHa a Institute of Materials Science, Vietnam Academy of Science and Technology (VAST) b Graduated University of Science and Technology, VAST c Small and Medium Enterprise Development and Support Center 1, STAMEQ, 8 Hoang Quoc Viet, Cau Giay, Hanoi, Vietnam d University of Science, Hue University, 77 Nguyen Hue str., Hue city, Vietnam † E-mail: hoipv@ Received 2 January 2018 Accepted for publication 6 May 2018 Published 23 June 2018 Abstract. In this paper, we overview some configurations of photonic devices for measuring mechanical strain and wavelength shift without use of spectrometer, which have been developed recently and demonstrated large potential application in sensing technique with low cost. There are three kinds of photonic sensor configurations to be presented: i) first of them is a fiber Bragg grating (FBG) for the measurement of mechanical dynamic strain of very small value using signal modulation on laser diode by composition of two wavelengths in the laser cavity; ii) second configuration is a FBG combined with a DFB laser diode whose emission wavelength controlled by laser temperature, and iii) last one uses a fiber ring laser from Erbium doped fiber and two FBG operated as reference and sensing probe. For the environment control, the etched-fiber Bragg grating (e-FBG) as sensing probe is very suitable for bio- and/or chemical sensors. The photonic sensors can increase sensitivity and measuring accuracy by narrow line-width of reflection laser spectra and, therefore, the sensors can determine a refractive index variation of 2 × 10−4 , which is similarly as use of a high resolution spectrometer. The experimental .
