Modeling noise and modulation performance of fiber grating external cavity lasers (original) (raw)
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Small-signal IM response of grating-terminated external cavity semiconductor lasers
IEEE Journal of Selected Topics in Quantum Electronics, 1995
Abstruct-The small-signal intensity modulation response and the CW noise spectrum of a semiconductor laser coupled to an external cavity are known to be enhanced in narrow peaks centerd around the harmonics of the cavity resonance frequency. We have previously shown that each resonance peak of the response exhibits an amplitude discontinuity near the harmonics of cavity resonance frequency. In this paper, we show that each peak of the noise spectrum is bifurcated into a pair of closely spaced peaks of different amplitudes and bandwidths. A comprehensive analytical model is developed to investigate the discontinuity of response peaks and to study the effect of various parameters on their bandwidth and modulation efficiency. It is shown that strong optical feedback, strong gain compression and dc bias above threshold reduce the modulation efficiency but increase the modulation bandwidth.
Small-signal circuit modeling for a grating external-cavity semiconductor laser
Journal of the Optical Society of America B, 1994
A sinusoidal small-signal circuit model is presented for an external-cavity semiconductor diode laser with either weak or strong external optical feedback provided by a grating. It is shown that the effects of optical feedback can be modeled by two voltage sources correlated to the modulated injection current of the diode laser. The magnitudes of these two voltage sources are proportional to the product of the optical feedback level and the modulation amplitude. This result supports the idea of modulating a diode laser by optical injection. The small-signal intensity modulation and FM response characteristics of this circuit model are also presented. The response curves exhibit oscillations with the periods determined by the modulation feedback phase delay. These results agree with the results obtained elsewhere. For a short external-cavity limit, the response curves are reduced to the curves obtained elsewhere for a diode laser without an external cavity.
New dynamic multimode model for external cavity semiconductor lasers
IEE Proceedings J Optoelectronics
A new, dynamic, time-domain, numerical model for external cavity lasers, based on the transmission-line laser model (TLLM), is introduced. This is able to show the evolution of spectra from large-signal modulated devices, even when the modulation pulsewidth is less than the external cavity round-trip delay. The model is demonstrated using short and long dispersionless cavities. Results in the time and spectral domains are in agreement with those of previous theoretical and experimental work.
Study of Microintegrated External-Cavity Diode Lasers: Simulations, Analysis, and Experiments
IEEE Journal of Quantum Electronics, 2015
This paper reports the results of numerical and experimental investigations of the dynamics of an external-cavity diode laser device composed of a semiconductor laser and an external Bragg grating, which provides optical feedback. Due to the influence of the feedback, this system can operate in different dynamic regimes. The traveling-wave model is used for simulations and analysis of the nonlinear dynamics in the considered laser device. Based on this model, a detailed analysis of the optical modes is performed, and the stability of the stationary states is discussed. It is shown that the results obtained from the simulation and analysis of the device are in a good qualitative agreement with the experimental findings.
Interference-filter-stabilized external-cavity diode lasers
Optics Communications, 2006
We have developed external-cavity diode lasers, where the wavelength selection is assured by a low loss interference filter instead of the common diffraction grating. The filter allows a linear cavity design reducing the sensitivity of the wavelength and the external cavity feedback against misalignment. By separating the feedback and wavelength selection functions, both can be optimized independently leading to an increased tunability of the laser. The design is employed for the generation of laser light at 698, 780 and 852 nm. Its characteristics make it a well suited candidate for space-born lasers.
IEEE Journal of Quantum Electronics, 2000
We have investigated the occurence of a second resonance frequency in distributed Bragg reflector laser diodes and the high modulation bandwidth resulting from it. The influence of different laser parameters has been theoretically investigated. It is also shown that a similar behavior can be obtained in laser diodes with a passive, low-loss, and gratingless external cavity. The possibilities of large-signal digital modulation are also investigated.
Influence of grating parameters on the linewidths of external-cavity diode lasers
Applied Optics, 2006
We investigate experimentally the influence of the grating reflectivity, grating resolution, and diode facet antireflection (AR) coating on the intrinsic linewidth of an external-cavity diode laser built with a diffraction grating in a Littrow configuration. Grating lasers at 399, 780, and 852 nm are determined to have typical linewidths between 250 and 600 kHz from measurements of their frequency noise power spectral densities. The linewidths are little affected by the presence of an AR coating on the diode facet but narrow as the grating reflectivity and grating resolution are increased, with the resolution exerting a greater effect. We also use frequency noise measurements to characterize a laser mount with improved mechanical stability.
Relative Intensity Noise Reduction by Optimizing Fiber Grating Fabry-Perot Laser Parameters
Ieee Journal of Quantum Electronics, 2012
A set of nonlinear rate equations that can describe an external cavity laser with any arbitrary external optical feedback (OFB) level are derived. A comprehensive study on the relative intensity noise (RIN) characteristics of a fiber grating Fabry-Perot is performed numerically. In this paper, fiber Bragg grating (FBG) is used as a wavelength lasing selective element to control the external OFB level, thereby control the RIN. In addition to the external OFB level, the effect of other external cavity parameters such as temperature, injection current, cavity volume, gain compression factor, and FBG parameters on RIN characteristics is investigated. The temperature dependence (TD) of RIN is calculated according to TD of laser parameters instead of well-known Parkove relationship. Results show that by optimization, the peak value of the RIN can be reduced down to around -150 dB/Hz. The optimum and the shortest external cavity length that provides the minimum RIN is found to be around 3.1 cm. In addition, by optimization, the relaxation oscillation frequency of RIN spectra is shifted toward around 5.6 GHz.
2010
This paper reports the results of numerical and experimental investigations of the dynamics of an external cavity diode laser device composed of a semiconductor laser and a distant Bragg grating, which provides an optical feedback. Due to the influence of the feedback, this system can operate at different dynamic regimes. The traveling wave model is used for simulations and analysis of the nonlinear dynamics in the considered laser device. Based on this model, a detailed analysis of the optical modes is performed, and the stability of the stationary states is discussed. It is shown, that the results obtained from the simulation and analysis of the device are in good agreement with experimental findings.
2002
Much research has been carried out on fibre Bragg grating (FBG) external cavity semiconductor lasers for application as stabilised carrier wave and modulated laser sources and as tuneable lasers. In this paper two novel FBG external cavity lasers are experimentally demonstrated. Both use the light reflected from the FBGs to force the lasers to operate at the Bragg wavelengths. They offer tuneable beat frequencies and are able to switch the polarisation and wavelength of the laser.