China
Africa
Explore chapters and articles related to this topic
Photonic Ultra-Short Pulse Generators
Published in Le Nguyen Binh, Photonic Signal Processing, 2019
One rim of about 3.042 km of dispersion compensating fiber (DCF), with a dispersion value of −98 ps/nm/km, was used in the experiment; the schematic of the experimental setup is shown in Figure 7.34. The variable optical attenuator used in the setup is to reduce the optical power of the pulse train generated by the mode-locked fiber ring laser, hence to remove the nonlinear effect of the pulse. A DCF length for 4x multiplication factor on the ~10 GHz signal is required and estimated to be 3.048173 km. The output of the multiplier (i.e., at the end of DCF) is then observed using Textronix CSA 8000 80E01 50 GHz Communications Signal Analyzer.
Fiber Limits
Published in David R. Goff, Kimberly Hansen, Michelle K. Stull, Fiber Optic Video Transmission, 2013
David R. Goff, Kimberly Hansen, Michelle K. Stull
In digital transmission, one can use an optical attenuator to determine receiver sensitivity by increasing the attenuation between a fiber optic transmitter and receiver connected with a short length of fiber. Usually a given bit error rate (BER) defines the receiver sensitivity limit; typical bit error rates include 10-9 or 10-12. Figures 6.10 and 6.11 illustrate a test setup for this measurement.
Testing & Measurement Techniques
Published in David R. Goff, Kimberly Hansen, Michelle K. Stull, Fiber Optic Reference Guide, 2002
David R. Goff, Kimberly Hansen, Michelle K. Stull
Fiber Optic Attenuator: A fiber optic attenuator, also called an optical attenuator, simulates the loss that would be caused by a long length of fiber. Typically, this device performs receiver testing. While an optical attenuator can simulate the optical loss of a long length of fiber, it cannot accurately simulate the dispersion that would be caused by a long length of fiber.
Gain clamping performance of Hafnia–bismuth–erbium co-doped fibre amplifier using lasing controlled structure with FBG
Published in Journal of Modern Optics, 2021
N.F. Zulkipli, S.A. Sadik, F.E. Durak, M.C. Paul, A. Altuncu, S.W. Harun
A tunable laser source (Santec TLS-200) was used with a variable optical attenuator (VOA) to obtain input signal with varying optical power levels. For the bidirectional pumping scheme, two semiconductor uncooled pump laser diodes operating at the 980 nm region were used. To suppress the undesired lasing oscillations caused by the connectors at both the ends, two isolators were used at the input and the output of the optical amplifier. In order to achieve gain clamping operation, two FBGs with the same Bragg reflection wavelength were utilized. FBG pairs used in the study have a high reflectivity of 95% and a 3-dB linewidth of 0.1 nm. To investigate the effect of the lasing controlled gain clamping structure formed with FBG pairs on the HB-EDFA performance, the FBG pairs with different reflection wavelengths are utilized and the best gain clamping performance of the FBG pairs with reflection wavelengths of 1534 nm and 1542 nm was presented. The gain and NF characterization of the proposed gain clamped HB-EDFA were realized with an optical spectrum analyser (OSA, Anritsu MS9710B).
Ultra-short pulse generating in erbium-doped fiber laser cavity with 8-Hydroxyquinolino cadmium chloride hydrate (8-HQCdCl2H2O) saturable absorber
Published in Journal of Modern Optics, 2021
Mustafa Mohammed Najm, Hamzah Arof, Bilal Nizamani, Ahmed Shakir Al-Hiti, Pei Zhang, Moh Yasin, Sulaiman Wadi Harun
Figure 3(a) shows the experimental arrangement for measuring the nonlinear absorption for the prepared 8-HQCdCl2H2O thin film. It consists of a mode-locked pulse source that has repetition rate, pulse width, and wavelength of 3.6 MHz, 1.02 ps, and 1562 nm, respectively. The mode-locked pulse was amplified by an erbium-doped fiber amplifier (EDFA), then the EDFA was linked to an optical attenuator for modifying laser output power. The attenuated output power was split into two sections by a 50:50 optical coupler (OC); 50% of light was launched into the 8-HQCdCl2H2O film for absorption measurement, and another half of light was used as a reference. The data recorded was analyzed as shown in Figure 3(b). It indicates that the 8-HQCdCl2H2O film exhibits a saturable absorption, non-saturable absorption, and saturable intensity of 18%, 70%, and 0.1 MW/cm2, respectively.
Narrow-linewidth passively Q-switched fibre laser based on microsphere resonator
Published in Journal of Modern Optics, 2020
Yajie Wu, Hong Zhang, Fangjie Wang, Jiulin Yang, Shutong Wang, Shouhuan Zhou
The nonlinear absorption of the SA was characterized by a standard two-arm transmission setup, as shown in Figure 1. The film was placed between two fibre connectors to form a fibre-integrated device. Then we measured the dependence of the transmission ratio of the device on the pump power density, by using a 1550 nm mode-locked laser with the repetition rate of 25.7 MHz and the pulse width of 52.5 ps. Variable optical attenuator (VOA) was used to vary the incident average power. A 90/10 optical coupler split the output from VOA into two parts. One output (10%) was directed into the first power meter, while another portion (90%) entered the graphene SA then exited into the second power meter. The result is depicted in Figure 2, the experimental data of the transmission is fitted according to the following formula: