In this paper, the feasibility of multimode fiber as pressure sensor is explore by using the straight structure of the fiber itself. The elastic mechanical model and the basic equation of the straight structure of the fiber is established. ANSYS software is used for the analysis of stress and strain distribution and the results show that the stress and strain of load section fiber are linearly related. In the experimental process, the straight structure fiber is used as the test unit and the change of the optical power is measured and analyzed during the pressure loading. The experimental results show that the linear correlation coefficient R2 of the pressure loading process from 0g to 400g is 0.9117 for the multi-mode fiber; and the linear correlation coefficient R2 of the pressure unloading process from 400g to 0g is 0.7061. So it can be concluded that the straight structure multimode fiber can be used as a pressure sensor.
A high resolution fiber optic spectrometer system was set up, which consists of a tunable laser, a fiber optic power meter, GPIB-USB data acquisition cards, and a computer control platform. The wavelength absolute accuracy of the tunable laser (Santec TSL-550) is±2.5pm, and the wavelength setting resolution can be 0.1pm, which makes the system features high resolution. However, the resolution of the laboratory fiber optic spectrometer (YOKOGAWA AQ6317C) can only be set to 20pm. The extinction ratio (ER), free spectral range (FSR) and the trough position of the spectrum of the microfiber knot resonator (MKR) is measured with our system and AQ6317C fiber optic spectrometer. The experimental results of the two methods show that the ER and FSR are offset by 0.675dB and 0.003nm, respectively, and the standard deviations are 0.17% and 0.43%, respectively. From the results, and the stability of MKR is considered, we conclude that the resolution of our system can be better than 1nm due to the resolution of the TSL-550 light source, and the overall standard deviation is also smaller, therefore, the repeatability and stability of our testing system are better than the AQ6317C fiber optic spectrometer, which can better meet the actual measurement requirements.
By now, it is still extremely challenging to accurately measure femto-Newton (10-15 N) optical forces. Here, a simple scheme of a suspended tapered nanofiber coupled with a glass substrate is demonstrated to generate and sense the fN optical force, where the ~10 nm deformation of the nanofiber can be resolved by white light interferometry and an ultra-low stiffness of 0.540 fN/nm is obtained for the suspended nanofiber through Brownian motion. Owing to the ultra-low stiffness of the nanofiber, the scheme provides a cost-effective method to sense and measure ultra-weak (5.2 fN) optical force. Moreover, the scheme also provides a simple way to exploit fN optical forces for implementation of micro-Watt all-optical devices.
Light control-light characteristics of a micro fiber (MF) coated with tungsten disulfide (WS2) nanosheets is demonstrated in this paper. A device with WS2-coated MF has been fabricated, and the transmitted optical powers of the device are measured with 405 and 660 nm pump lasers. By tuning the pump lasers, we achieve the all light controllable sensing of WS2-coated MF over a broadband wavelength range from 1520 to 1620 nm, offering competitive sensities of 0.238 and 0.136 dB/mW for 405 and 660 nm pump lasers, respectively. In addition, The rise and fall times of the transient response to pump lasers are also measured. For the 405 nm laser, the rise and fall times of the transient response are 0.32s and 0.42s, respectively. For 660 nm laser, the response times toward the presence (removal) of the pump light transient response are 0.28s and 0.37s, respectively. Experimental results indicate that the device integrated with WS2 could hold promising potentials in photoelectric and photonic applications.
We propose the electro-optic mode deflection devices based on annealed proton exchange (APE) waveguides in lithium niobate with microstructured electrodes. Two mode deflection devices with right-triangle-shaped electrodes (Device A) and isosceles-triangle-shaped electrodes (Device B) are investigated. Taking advantage of the refractive index prism array formed when applying an external voltage to the electrodes, the mode can be deflected. Beam smoothing can be achieved by applying alternating voltages. A∼1.28 μm beam deflection is obtained by applying a voltage (20 V) for Device A. For Device B, a 3.52 μm beam deflection is obtained by applying a -15 V voltage to the electrodes. Device B has a horn-shaped input waveguide which ensures that the output is a quasi-single mode. The mode quality of the deflection beam is also quantified by the CMOS camera. Smoothing the non-uniform density distribution of light beam is confirmed by averaging over 69 images taken by the CMOS camera with alternating voltage. These electro-optic mode deflection devices have potential applications in electro-optic sampling, high-speed optical switch, and beam smoothing of a high-power laser.
Optical fibers have long been the backbone of modern communication system. One way of extending the capability of optical fibers is to thin down the core sizes as microfiber which facilitates light-matter interaction through evanescent light. Among different microfiber based structure, the microfiber knot resonator (MKR) is a resonant structure which finds applications in lasing, filtering and optical switching [1-2]. Particularly, when the MKR structure is combined with functional two-dimensional materials, a large panel of devices can be achieved via the investigation of variations in resonance properties.
Here, a layered metal dichalcogenide semiconductor tin disulfide (SnS2), characterized with high intrinsic electron mobility and strong absorption in the visible light regime [3], is chosen to be coated onto MKR. The all-optical control of light functionality is demonstrated in MKR with SnS2 structure where the signal light power is controlled by the external violet pump power via the absorption property of SnS2. The device fabrication, characterization and obtained experimental results will be presented in the talk.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.