Loading [MathJax]/extensions/TeX/extpfeil.js
Study on Frequency Coherence Properties of Light Beams | IEEE Journals & Magazine | IEEE Xplore

Study on Frequency Coherence Properties of Light Beams


Abstract:

This paper presents a new concept of frequency coherence in the frequency-time domain to describe the field correlations between two lightwaves with different frequencies...Show More

Abstract:

This paper presents a new concept of frequency coherence in the frequency-time domain to describe the field correlations between two lightwaves with different frequencies. The coherence properties of the modulated beams from lightwave sources with different spectral widths and the modes of Fabry-Perot (FP) laser are investigated. It is shown that the lightwave and its corresponding sidebands produced by the optical intensity modulation are perfectly coherent. The measured linewidth of the beat signal is narrow and almost identical no matter how wide the spectral width of the beam is. The frequency spacing of the adjacent FP modes is beyond the operation frequency range of the measurement instruments. In our experiment, optical heterodyne technique is used to investigate the frequency coherence of the modes of FP laser by means of the frequency shift induced by the optical intensity modulation. Experiments show that the FP modes are partially coherent and the mode spacing is relatively fixed even when the wavelength changes with ambient temperature, bias current and other factors. Therefore, it is possible to generate stable and narrow-linewidth signals at frequencies corresponding to several mode intervals of the laser.
Published in: IEEE Journal of Quantum Electronics ( Volume: 45, Issue: 5, May 2009)
Page(s): 514 - 522
Date of Publication: 17 April 2009

ISSN Information:

References is not available for this document.

I. Introduction

Coherence in optics is an important parameter that quantifies the quality of interference [1], [2]. The most commonly used concepts are temporal and spatial coherence, which have been extensively studied in the past [3]– [6]. The concept of field correlations in the space-time domain has been expressed clearly in [1]. Spatial coherence describes the correlation between signals at different points in space. Temporal coherence describes the correlation between signals observed at different moments. In a typical interferometer, a lightwave is split into two beams, and the two beams are recombined together with different delay times. The two beams are perfectly coherent when the lengths of the two paths are identical. For a certain delay difference, the degree of coherence depends on the linewidth and wavelength stability of the light beam. There are other concepts on coherence in accordance with different physical parameters, such as polarization coherence, quantum coherence, and spectral coherence. Spectral correlation, which is not so widely used as temporal and spatial coherence, describes the correlation that exists between the spectral components at a given frequency in the light oscillations at two points in a stationary optical field [1].

Select All
1.
L. Mandel and E. Wolf, "Spectral coherence and the concept of cross-spectralpurity", J. Opt. Soc. Amer., vol. 66, pp. 529-535, Jun. 1976.
2.
M. Born and E. Wolf, Principles of Optics, New York:Cambridge Univ. Press, 1999.
3.
L. Mandel and E. Wolf, "Coherence properties of optical fields", Rev. Mod. Phys., vol. 37, pp. 231-287, 1965.
4.
R. Loudon, The Quantum Theory of Light, New York:Oxford Univ. Press, 1983.
5.
L. Mandel, Optical Coherence and Quantum Optics, New York:Cambridge Univ. Press, 1995.
6.
A. Marathay, Elements of Optical Coherence Theory, New York:Wiley, 1982.
7.
Coherence (physics), 2009., [online] Available: http://en.wikipedia.org/wiki/Coherence_(physics).
8.
E. Eichen and A. Silletti, "Bandwidth measurements of ultrahigh-frequencyoptical detectors using the interferometric FM sideband technique", J. Lightw. Technol., vol. 5, no. 10, pp. 1377-1381, Oct. 1987.
9.
D. M. Baney and W. V. Sorin, "Measurement of a modulatedDFB laser spectrum using gated delayed self-homodyne technique", Electron. Lett., vol. 24, pp. 669-670, May 1988.
10.
A. Yariv, Optical Electronics in Modern Communications, New York:Oxford Univ. Press, 1997.
11.
H. Altug, D. Englund and J. Vuckovic, "Ultrafast photonic crystalnanocavity laser", Nature Phys., vol. 2, no. 7, pp. 484-488, Jul. 2006.
12.
N. H. Zhu, J. M. Wen, W. Chen and L. Xie, "Hyperfine spectral structure of semiconductor lasers", Phys. Rev. A, vol. 76, pp. 063821, Dec. 2007.
13.
K. Sato, "Optical pulse generation usingFabryPerot lasers under continuous wave operation", IEEE J. Sel. Topics Quantum Electron., vol. 9, no. 5, pp. 1288-1293, Sep./Oct. 2003.
14.
Y. Katagiri and A. Takada, "Synchronized pulse-train generationfrom passively mode-locked semiconductor lasers by a phase-locked loop usingoptical modulation sidebands", Electron. Lett., vol. 32, pp. 1892-1893, Sep. 1996.
15.
K. Sato, "100 GHz optical pulse generationusing FabryPerot laser under continuous wave operation", Electron. Lett., vol. 37, no. 12, pp. 763-764, Jun. 2001.
16.
N. H. Zhu, J. M. Wen, H. P. Song, S. J. Zhang and L. Xie, "Measurement of small-signal and large-signalresponses of packaged laser modules at high temperature", Opt. Quantum Electron., vol. 38, pp. 1245-1257, Dec. 2006.
17.
G. Grosskopf, D. R. Eggemann, S. Bauer, C. Bornholdt, M. Moehrle and B. Sartorrius, "Optical millimeter-wave generation and wirelessdata transmission using a dual-mode laser", IEEE Photon. Technol. Lett., vol. 12, no. 12, pp. 1692-1694, Dec. 2000.
18.
M. Maeda, T. Hirata, M. Suehiro, M. Hihara, A. Yamaguchi and H. Hosomatsu, "Photonic integrated circuitcombining two GaAs distributed Bragg reflector laser diodes for generationof the beat signal", Jpn. J. Appl. Phys., vol. 31, pp. L183-L185, Feb. 1992.
19.
M. L. Osowski, R. M. Lammert and J. J. Coleman, "A dual-wavelength source withmonolithically integrated electroabsorption modulators and Y-junction couplerby selective-area MOCVD", IEEE Photon. Technol. Lett., vol. 9, no. 2, pp. 158-160, Feb. 1997.
20.
J. H. Teng, S. J. Chua, Z. H. Zhang, Y. H. Huang, G. Li and Z. J. Wang, "Dual-wavelength laser source monolithicallyintegrated with Y-junction coupler and isolator using quantum-well intermixing", IEEE Photon. Technol. Lett., vol. 12, no. 10, pp. 1310-1312, Oct. 2000.
21.
D. Wake, C. R. Lima and P. A. Davies, "Optical generation of millimeter-wavesignals for fiber-radio systems using a dual-mode DFB semiconductor laser", IEEE Trans. Microw. Theory Tech., vol. 43, no. 9, pp. 2270-2276, Sep. 1995.
22.
J. W. Dawson, N. Park and K. J. Vahala, "An improved delayed self-heterodyne interferometerfor linewidth measurements", IEEE Photon. Technol. Lett., vol. 4, no. 9, pp. 1063, Sep. 1992.
23.
M. Han and A. Wang, "Analysis of a loss-compensated recirculatingdelayed self-heterodyne interferometer for laser linewidth measurement", Appl. Phys. B, vol. 81, pp. 53-58, Jul. 2005.

References

References is not available for this document.