| 1. |
- Sampson, Joshua N., et al.
(författare)
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Analysis of Heritability and Shared Heritability Based on Genome-Wide Association Studies for 13 Cancer Types
- 2015
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Ingår i: Journal of the National Cancer Institute. - : Oxford University Press (OUP). - 0027-8874 .- 1460-2105. ; 107:12
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Tidskriftsartikel (refereegranskat)abstract
- Background: Studies of related individuals have consistently demonstrated notable familial aggregation of cancer. We aim to estimate the heritability and genetic correlation attributable to the additive effects of common single-nucleotide polymorphisms (SNPs) for cancer at 13 anatomical sites. Methods: Between 2007 and 2014, the US National Cancer Institute has generated data from genome-wide association studies (GWAS) for 49 492 cancer case patients and 34 131 control patients. We apply novel mixed model methodology (GCTA) to this GWAS data to estimate the heritability of individual cancers, as well as the proportion of heritability attributable to cigarette smoking in smoking-related cancers, and the genetic correlation between pairs of cancers. Results: GWAS heritability was statistically significant at nearly all sites, with the estimates of array-based heritability, h(l)(2), on the liability threshold (LT) scale ranging from 0.05 to 0.38. Estimating the combined heritability of multiple smoking characteristics, we calculate that at least 24% (95% confidence interval [CI] = 14% to 37%) and 7% (95% CI = 4% to 11%) of the heritability for lung and bladder cancer, respectively, can be attributed to genetic determinants of smoking. Most pairs of cancers studied did not show evidence of strong genetic correlation. We found only four pairs of cancers with marginally statistically significant correlations, specifically kidney and testes (rho = 0.73, SE = 0.28), diffuse large B-cell lymphoma (DLBCL) and pediatric osteosarcoma (rho = 0.53, SE = 0.21), DLBCL and chronic lymphocytic leukemia (CLL) (rho = 0.51, SE = 0.18), and bladder and lung (rho = 0.35, SE = 0.14). Correlation analysis also indicates that the genetic architecture of lung cancer differs between a smoking population of European ancestry and a nonsmoking Asian population, allowing for the possibility that the genetic etiology for the same disease can vary by population and environmental exposures. Conclusion: Our results provide important insights into the genetic architecture of cancers and suggest new avenues for investigation.
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| 2. |
- Wang, Zhaoming, et al.
(författare)
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Imputation and subset-based association analysis across different cancer types identifies multiple independent risk loci in the TERT-CLPTM1L region on chromosome 5p15.33
- 2014
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Ingår i: Human Molecular Genetics. - : Oxford University Press (OUP). - 0964-6906 .- 1460-2083. ; 23:24, s. 6616-6633
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Tidskriftsartikel (refereegranskat)abstract
- Genome-wide association studies (GWAS) have mapped risk alleles for at least 10 distinct cancers to a small region of 63 000 bp on chromosome 5p15.33. This region harbors the TERT and CLPTM1L genes; the former encodes the catalytic subunit of telomerase reverse transcriptase and the latter may play a role in apoptosis. To investigate further the genetic architecture of common susceptibility alleles in this region, we conducted an agnostic subset-based meta-analysis (association analysis based on subsets) across six distinct cancers in 34 248 cases and 45 036 controls. Based on sequential conditional analysis, we identified as many as six independent risk loci marked by common single-nucleotide polymorphisms: five in the TERT gene (Region 1: rs7726159, P = 2.10 × 10(-39); Region 3: rs2853677, P = 3.30 × 10(-36) and PConditional = 2.36 × 10(-8); Region 4: rs2736098, P = 3.87 × 10(-12) and PConditional = 5.19 × 10(-6), Region 5: rs13172201, P = 0.041 and PConditional = 2.04 × 10(-6); and Region 6: rs10069690, P = 7.49 × 10(-15) and PConditional = 5.35 × 10(-7)) and one in the neighboring CLPTM1L gene (Region 2: rs451360; P = 1.90 × 10(-18) and PConditional = 7.06 × 10(-16)). Between three and five cancers mapped to each independent locus with both risk-enhancing and protective effects. Allele-specific effects on DNA methylation were seen for a subset of risk loci, indicating that methylation and subsequent effects on gene expression may contribute to the biology of risk variants on 5p15.33. Our results provide strong support for extensive pleiotropy across this region of 5p15.33, to an extent not previously observed in other cancer susceptibility loci.
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| 3. |
- Chen, Daru, et al.
(författare)
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Actively mode-locked fiber laser based on hybrid Raman and erbium-doped fiber gains
- 2007
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Ingår i: Microwave and optical technology letters (Print). - : Wiley. - 0895-2477 .- 1098-2760. ; 49:10, s. 2339-2341
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Tidskriftsartikel (refereegranskat)abstract
- An actively mode-locked fiber laser (AMLFL) based on the hybrid gain of a dispersion-shifted fiber (as the Raman gain medium) and an Erbium-doped fiber (EDF) is introduced. The fiber Raman gain mechanism can effectively suppress the gain competition of an EDF, which usually results into the supermode noise in an actively mode-locked EDF laser. We experimentally demonstrated a stable AMLFL with the repetition of about 5 GHz, in which the supermode noise is believed to be suppressed by employing the hybrid gain medium.
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| 4. |
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| 5. |
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| 6. |
- Chen, Daru R., et al.
(författare)
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Wavelength-spacing continuously tunable multi-wavelength SOA-fiber ring laser based on Mach-Zehnder interferometer
- 2008
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Ingår i: Optics and Laser Technology. - : Elsevier BV. - 0030-3992. ; 40:2, s. 278-281
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Tidskriftsartikel (refereegranskat)abstract
- A Mach-Zehnder interferometer (MZI) which is used as a wavelength-spacing tunable comb filter in a fiber ring laser is built by employing an optical variable delay line (OVDL). Stable multi-wavelength semiconductor optical amplifier (SOA)-fiber ring laser based on an SOA and the MZI comb filter is achieved. Wavelength spacing can be continuously tuned by adjusting the OVDL and, as an example, multi-wavelength lasing with the wavelength spacing of 0.4, 0.8, or 1.6 nm is demonstrated. The output of the proposed multi-wavelength SOA-fiber ring laser is quite stable at room temperature and the output spectrum can be adjusted by controlling the bias current of the SOA.
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| 7. |
- Chen, Daru, et al.
(författare)
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Single-longitudinal-mode erbium-doped fiber laser based on a fiber Bragg grating Fabry-Perot filter
- 2007
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Ingår i: Laser physics. - 1054-660X .- 1555-6611. ; 17:10, s. 1246-1248
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Tidskriftsartikel (refereegranskat)abstract
- A novel single-longitudinal-mode (SLM) erbium-doped fiber laser with a simple linear cavity based on a fiber Bragg grating Fabry-Perot filter (FBG-FPF) and a narrowband (similar to 0.06 nm) FBG is proposed and demonstrated experimentally. Two uniform FBGs form the FBG-FPF, which has two ultranarrow transmission bands with a bandwidth of 0.12 pm and a wavelength spacing of 0.095 nm. By slightly tuning the central wavelength of the narrowband FBG, SLM lasing at 1549.658 or 1549.563 nm (corresponding to the two transmission peaks of the FBG-FPF) is achieved with a laser output power of similar to 4 mW, when the pump power is similar to 75 mW.
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| 8. |
- Chen, Daru, et al.
(författare)
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Some switchable dual-wavelength fibre lasers based on fibre Bragg grating feedback
- 2006
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Ingår i: Proceedings of SPIE, the International Society for Optical Engineering. - : SPIE. - 0277-786X .- 1996-756X. ; 6351, s. U864-U872
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Tidskriftsartikel (refereegranskat)abstract
- Two methods to achieve dual-wavelength switching in a fibre laser are proposed and two corresponding switchable dual-wavelength fibre lasers based on fibre Bragg grating (FBG) feedback are demonstrated in this paper. In one proposed fibre laser, both Raman and Erbium-doped fibre (EDF) pumps are employed and the dual-wavelength switching is achieved by controlling the power of the Raman pump. In the other proposed fibre laser, an injection technique is used and the dual-wavelength switching is realized by controlling the power of the injection laser. The detailed behavior of the dual-wavelength switching in the two fibre lasers is experimentally studied and the principle is explained physically.
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| 9. |
- Chen, Daru
(författare)
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Stable multi-wavelength erbium-doped fiber laser based on a photonic crystal fiber Sagnac loop filter
- 2007
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Ingår i: LASER PHYSICS LETTERS. - : IOP Publishing. - 1612-2011 .- 1612-202X. ; 4:6, s. 437-439
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Tidskriftsartikel (refereegranskat)abstract
- A multi-wavelength erbium-doped fiber laser based on a Sagnac loop fiber which is formed by a birefringent and highly nonlinear photonic crystal fiber (PCF), a 3-dB optical coupler and two polarization controllers is proposed. The PCF Sagnac loop filter is used as comb filter and power-stabilizing and equilibrizing component in the multi-wavelength erbium-doped fiber laser. Stable multi-wavelength lasing at room temperature is achieved, owing to the contributions of both the birefringent property and the four-wave mixing effect of the PCF.
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| 10. |
- Chen, Daru, et al.
(författare)
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Switchable and tunable Erbium-doped fiber ring laser incorporating a birefringent and highly nonlinear photonic crystal fiber
- 2007
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Ingår i: LASER PHYSICS LETTERS. - : IOP Publishing. - 1612-2011 .- 1612-202X. ; 4:5, s. 368-370
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Tidskriftsartikel (refereegranskat)abstract
- A birefringent and highly nonlinear photonic crystal fiber is employed in an Erbium doped fiber ring laser, which can operate with dual-wavelength lasing or single-wavelength lasing. Both stable dual-wavelength lasing and tunable single-wavelength lasing are achieved by adjusting a polarization controller in the ring cavity. The experimental results show that the output of the proposed fiber ring laser is rather stable at two different operation modes.
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| 11. |
- Chen, Daru, et al.
(författare)
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Switchable dual-wavelength Raman erbium-doped fibre laser
- 2006
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Ingår i: Electronics Letters. - : Institution of Engineering and Technology (IET). - 0013-5194 .- 1350-911X. ; 42:4, s. 202-204
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Tidskriftsartikel (refereegranskat)abstract
- A fibre Bragg grating feedback fibre laser with both Raman and erbium-doped fibre pumps is proposed. Dual-wavelength switching is achieved by controlling the power of the Raman pump. The characteristics of the dual-wavelength switching are studied experimentally, and the mechanism is explained physically.
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| 12. |
- Chen, Daru, et al.
(författare)
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Tunable and injection-switchable erbium-doped fiber laser of line structure
- 2007
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Ingår i: Microwave and optical technology letters (Print). - : Wiley. - 0895-2477 .- 1098-2760. ; 49:4, s. 765-768
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Tidskriftsartikel (refereegranskat)abstract
- A tunable and injection-switchable erbium-doped fiber (EDF) laser is proposed based on a line structure formed by a fiber Sagnac loop reflector and an fiber Bragg grating (FBG). Wavelength switching is achieved by controlling the power of the tunable injection laser. The self-seeded wavelength corresponding to the Bragg wavelength of the FBG can be tuned by, for example, heating the FBG, and the injection wavelength can be tuned over a wide range of about 50 nm. The characteristics of the wavelength switching for different levels of the EDF pump power and different wavelengths of the injection laser are studied experimentally. The present fiber laser has the advantages of tunability, stability, low amplified spontaneous emission noise, and high injection efficiency when compared with a fiber ring laser. Rapid wavelength switching is expected and the transient switching response of the laser is also studied.
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| 13. |
- Chen, Daru, et al.
(författare)
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Ultrahigh bireffingent photonic crystal fiber with ultralow confinement loss
- 2007
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Ingår i: IEEE Photonics Technology Letters. - 1041-1135 .- 1941-0174. ; 19:2-4, s. 185-187
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Tidskriftsartikel (refereegranskat)abstract
- A photonic crystal fiber (PCF) with circular air holes in the fiber cladding and elliptical air holes in the fiber core is proposed. According to calculation, both ultrahigh birefringence (larger than 0.01) and ultralow confinement loss (less than 0.001 dB/km) can be achieved simultaneously over a large wavelength range for a PCF with only four rings of circular air holes in the fiber cladding. The confinement loss in this PCF can be effectively reduced while the birefringence almost remains the same. The proposed design of the PCF is a solution to the tradeoff between the birefringence and the confinement loss for the originally reported highly birefringent elliptical-hole PCF. Moreover, an approach to modify the effective index of fiber core is also suggested in this letter.
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| 14. |
- Chen, Daru, et al.
(författare)
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Wavelength-spacing continuously tunable multiwavelength erbium-doped fibre laser based on DSF and MZI
- 2007
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Ingår i: Electronics Letters. - : Institution of Engineering and Technology (IET). - 0013-5194 .- 1350-911X. ; 43:9, s. 524-525
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Tidskriftsartikel (refereegranskat)abstract
- A novel multiwavelength erbium-doped fibre laser is proposed by incorporating a section of dispersion-shifted fibre (DSF) and a Mach-Zehnder interferometer (MZI). The wavelength spacing of the fibre laser can be continuously tuned by adjusting an optical variable delay line in the MZI-based comb filter. Stable multiwavelength lasing at room temperature with the standard ITU (International Telecommunication Union) channel spacing of 0.2 nm (25 GHz), 0.4 nm (50 GHz), 0.8 nm (100 GHz) or 1.6 nm (200 GHz) is demonstrated.
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| 15. |
- Chen, Daru, et al.
(författare)
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Wavelength-spacing tunable multi-wavelength fiber lasers based on hybrid gain medium and Mach-Zehnder interferometer
- 2007
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Ingår i: 2007 Pacific Rim Conference on Lasers and Electro-Optics. - : IEEE. - 1424411734 - 9781424411733 ; , s. 4391428-
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Konferensbidrag (refereegranskat)abstract
- Wavelength-spacing continuously tunable multi-wavelength fiber lasers based on a Mach-Zehnder interferometer comb filter are achieved. Stable multi-wavelength lasing based on hybrid gains of Erbium-doped fiber amplification and fiber Raman amplification (semiconductor optical amplification) is demonstrated.
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| 16. |
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| 17. |
- Gao, Shiming, et al.
(författare)
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Bandwidth enhancement methods of telecom-region entangled twin photons via quasi-phase-matched spontaneous parametric down-conversion
- 2006
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Ingår i: Journal of nonlinear optical physics and materials. - 0218-8635. ; 15:4, s. 513-521
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Tidskriftsartikel (refereegranskat)abstract
- We theoretically present the bandwidth enhancement methods of the telecom-region entangled twin photons generated by quasi-phase-matched (QPM) spontaneous parametric down-conversion (SPDC) in periodically poled lithium niobate (PPLN) crystals. By using type I (e --> e + e) SPDC, the degenerate entangled twin photons will have a broad bandwidth and it can be further enhanced by shortening the crystal length, detuning the pump wavelength or adjusting the working temperature of the PPLN crystal. This principle provides the possibility to introduce wavelength-division-multiplexed technique into quantum information systems.
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| 18. |
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| 19. |
- Jiang, Meng, et al.
(författare)
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Multiplexing Scheme of Long-Period Grating Sensors Based on a Modified Optical Frequency Domain Reflectometry
- 2008
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Ingår i: IEEE Photonics Technology Letters. - 1041-1135 .- 1941-0174. ; 20:21-24, s. 1962-1964
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Tidskriftsartikel (refereegranskat)abstract
- We propose a novel quasi-real-time sensing scheme by employing a modified optical frequency domain reflectometry technique to multiplex long-period grating (LPG) sensors of transmission mode. Different sensing signals are demodulated by different beat signals through presetting different values for the optical path differences between the measuring arms and a static reference arm. The amplitude of each beat signal is associated with the transmissivity of a sensing LPG. The present multiplexing scheme has the advantages of real-time, high speed, high sensitivity, large capacity, and high resolution over an intermediate length. A measurement of fiber bending curvature is demonstrated to verify good performances of the present LPG sensing system.
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| 20. |
- Jiang, Wei, et al.
(författare)
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An extended FDTD method with inclusion of material dispersion for the full-vectorial analysis of photonic crystal fibers
- 2006
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Ingår i: Journal of Lightwave Technology. - 0733-8724 .- 1558-2213. ; 24:11, s. 4417-4423
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Tidskriftsartikel (refereegranskat)abstract
- An extended finite-difference time-domain (FDTD) method with inclusion of material dispersion for the full-vectorial analysis of photonic crystal fibers (PCFs) is presented in this paper. In order for this extended FDTD method to obtain a fast convergence and high accuracy, a constitutive-parameter averaging technique is employed. Numerical results for a typical PCF verify the validity of the extended FDTD method. With this FDTD mode solver, a new birefringent PCF is also investigated, and interesting results are obtained in this paper.
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| 21. |
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| 22. |
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| 23. |
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| 24. |
- Sun, Bing, et al.
(författare)
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Wavelength-Spacing-Tunable Double-Pumped Multiwavelength Optical Parametric Oscillator Based on a Mach-Zehnder Interferometer
- 2012
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Ingår i: Journal of Lightwave Technology. - 0733-8724 .- 1558-2213. ; 30:12, s. 1937-1942
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Tidskriftsartikel (refereegranskat)abstract
- A novel double-pumped ring cavity multiwavelength fiber optical parametric oscillator (MW-FOPO) with tunable wavelength spacing is proposed. In the MW-FOPO, we utilize a highly nonlinear dispersion-shifted fiber as the gain medium and a Mach-Zehnder interferometer as the comb-like filter. Twenty-four-wavelength lasing of the double-pumped MW-FOPO with a ripple less than +/- 4.3 dB and a wavelength spacing of about 0.8 nm in a wavelength range from 1541 to 1558 nm is experimentally demonstrated. The wavelength spacing can be continuously tuned and multiwavelength lasings with wavelength spacings of 0.08, 0.2, 0.4, and 0.8 nm are demonstrated, respectively. We discussed the power stability of the multiwavelength lasing of the double-pumped MW-FOPO. A comparison of the output spectra among the double-pumped MW-FOPO, the single-pumped MW-FOPO, and the multiwavelength erbium-doped fiber laser is also presented.
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| 25. |
- Wei, Yizhen, et al.
(författare)
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Widely tunable L-band brillouin fiber laser incorporating a bismuth-based erbium-doped fiber
- 2009
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Ingår i: Optics InfoBase Conference Papers. - Washington, D.C. : OSA. - 9781557528773
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Konferensbidrag (refereegranskat)abstract
- We proposed a widely tunable single-wavelength Brillouin fiber laser (BFL) by employing a bismuth-based erbium-doped fiber (Bi-EDF). The BFL operates in a range from 1555 nm to 1632 nm, which is the widest to the best of our knowledge. It's an attractive narrow linewidth laser source on the L-band.
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