A hollow anti-resonant fiber with nested and double cladding structure is proposed. By optimizing the structural parameters, the confinement loss reaches 4 × 10 − 4 dB / km at 1.55 μm, and the ratio of high-order mode loss to fundamental mode loss also reaches 20,000. In the O + E + S + C + L + U band, the loss is <0.01 dB / km and the ratio of high-order mode loss to fundamental mode loss is >103, indicating that the designed fiber has excellent single-mode characteristics and wide bandwidth. In addition, the manufacturing tolerance of the fiber is also discussed. It is found that the loss can still be maintained below 0.01 dB / km within the tolerance range of 8%. Therefore, we believe that the fiber has potential applications in near-infrared communication and data transmission.
We designed an all-normal flat near-zero dispersion As2S3 photonic crystal fiber (PCF) with orderly arranged air hole rings for generating an orbital angular momentum (OAM) supercontinuum (SC). We optimized the characters of chromatic dispersion and confinement loss compared with previous studies by carefully engineering the PCF. Simulation results show that, by launching a 100 fs 250 kW chirp-free hyperbolic secant pulse at 7 μm into a 5-mm designed PCF, a 9471-nm SC of OAM1,1 forms from 757 to 10228 nm at a −40 dB level, which covers a 3.7-octave bandwidth. As the peak power increases, the higher-order OAM with a flatter chromatic dispersion profile in the normal dispersion region has a wider bandwidth. They are all highly coherent in the whole spectral range.
A hollow-core antiresonant fiber (HC-ARF) using nested hybrid silica/silicon cladding is proposed for single-polarization single-mode (SPSM) and broadband. The HC-ARF design consists of four cladding tubes with nested tubes, and a cladding tube with an inner surface coated with silicon. Single-polarization guidance is realized by adjusting the thickness of the silicon layer to control the coupling between the y-polarization and cladding mode, and by optimizing the diameter of the nested tube, the high-order modes (HOMs) can be significantly suppressed. The simulation results show that the performance of SPSM can be improved by selecting appropriate structural parameters. The polarization extinction ratio (PER) is up to 139,804 and the y-polarization loss is 133 dB / m, the x-polarization loss is as low as 0.00095 dB / m at 1550 nm. Moreover, high-order mode extinction ratio (HOMER) between the HOMs and x-polarization, as high as 40,360, is obtained in proposed fiber with HOMs loss of 32.38 dB / m. Particularly, the proposed fiber also has a bandwidth of 230 nm (1450 to 1680 nm) with x-polarization mode loss <1 and 0.08 dB / m bending loss when the fiber is bent in the y-direction at a bending radius of 5 cm. The proposed fiber has potential applications in short-distance, polarization-sensitive fiber systems.
With the development of science and technology, all teachers in the college will face how to stimulate the undergraduate student’s ability and make them to be an excellent engineer. For solving these questions, a new scheme with three steps has been designed. First, students will participate in the class teaching activity not only teacher. It will encourage them to read many extracurricular books and articles. Second, they will be required to think and design more new experiments after complete all experiment about the textbook and join more competition of the innovation and entrepreneurship. Third, some students who have more time and ability can early enter into his advisor professor’s lab to join various science and technology project. By this scheme, it will be realized to improve student’s innovation ability and be a brilliant engineer.
Different higher education backgrounds in China and Germany led to challenges in the curriculum design at the beginning of our cooperative bachelor program in Optoelectronics Engineering. We see challenges in different subject requirements from both sides and in the German language requirements for Chinese students. The curriculum was optimized according to the ASIIN criteria, which makes it acceptable and understandable by both countries. German students are integrated into the Chinese class and get the same lectures like their Chinese colleagues. Intercultural and curriculum challenges are successfully solved. The results are summarized to provide an example for other similar international programs.
A microelectromechanical system (MEMS) mirror based endoscopic swept-source optical coherence tomography (SS-OCT) system that can perform three-dimensional (3-D) imaging at high speed is reported. The key component enabling 3-D endoscopic imaging is a two-axis MEMS scanning mirror which has a 0.8×0.8 mm 2 mirror plate and a 1.6×1.4 mm 2 device footprint. The diameter of the endoscopic probe is only 3.5 mm. The imaging rate of the SS-OCT system is 50 frames/s . OCT images of both human suspicious oral leukoplakia tissue and normal buccal mucosa were taken in vivo and compared. The OCT imaging result agrees well with the histopathological analysis.
A method to calculate the optical constants (refractive index n, film thickness d and extinction coefficient k) of
double-coated thin film by use of transmission spectrum is described in this paper. For double-coated glass films, the
relationship between T, λ, n, k and d is analyzed theoretically. Then the method to determine these optical parameters by
curve fitting is introduced. Several samples with different Sn concentrations have been prepared. According to the
method mentioned above, we calculate the coefficients of Sn-doped SiO2 films produced by Sol-gel method. Two kinds
of expressions for the refractive index n are introduced. One is Cauthy model. The other is defined as Polynomial model.
Also the expressions for k are given similarly. At last, the experimental curves are fitted according to the transmittance
formula. Results show that the refractive index becomes larger with the increase of Sn in the compound. Also, it turns out
that the refractive index decreases when the wavelength increases. This method combines the extreme point method with
the whole transmission spectra fitting method. This can improve the fitting accuracy.
Waveguide multiplayer optical memory is a kind of new 3D optical memory based on new principle. It can read the data by utilizing the effect of scattering light of waveguide defect. In the experiment, we use PMT to detect the scattering light, so how to process and collect the output of the PMT is a key technique which must be dealt with. In the experiment, we establish a set of experiment equipment to measure and collect the output of PMT. This paper introduces this experiment equipment and the analysis of the data collected. The elementary experiment result indicates that this system can realize processing and collection of the output of PMT and we can distinguish and measure the change of the signal while there is a information pit or not.
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.