Analysis of the linewidth of a grating-feedback GaAlAs laser

Genty, Goëry; Gröhn, Andreas; Talvitie, H.; Kaivola, Matti; Ludvigsen, Hanne

doi:10.1109/3.880660

Cited by 30 publications

(8 citation statements)

References 22 publications

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“…Because the back facet of the gain chip was uncoated, we encountered the usual coupled cavity problem (12), where the spectral output is governed by the FP modes of the gain chip as well as the modes of the overall external cavity. To minimize the effect of spectral mode hops across the modes of the external cavity, we selected a long external cavity of Ϸ1 m, yielding FP mode spacing of Ϸ150 MHz.…”

Section: Methodsmentioning

confidence: 99%

Sub-parts-per-billion level detection of NO ₂ using room-temperature quantum cascade lasers

Pushkarsky

Tsekoun

Dunayevskiy

et al. 2006

Proc. Natl. Acad. Sci. U.S.A.

122

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We report the sub-parts-per-billion-level detection of NO2 using tunable laser-based photoacoustic spectroscopy where the laser radiation is obtained from a room-temperature continuous-wave high-power quantum cascade laser operating in an external grating cavity configuration. The continuously tunable external grating cavity quantum cascade laser produces maximum single-frequency output of Ϸ300 mW tunable over Ϸ350 nm centered at 6.25 m. We demonstrate minimum detection level of Ϸ0.5 parts per billion of NO2 in the presence of humidified air.IR lasers ͉ NO2 spectroscopy ͉ photoacoustic spectroscopy ͉ sub-parts-per-billion detection of gases R eal-time trace-level gas detection is an area of fast growth with applications in such diverse fields as medical diagnostics, process control, national security, and environmental airquality monitoring. Techniques based on the measurement of optical absorption using tunable laser sources are attractive detection methods because of their intrinsic sensitivity and selectivity, i.e., an ability for discriminating against interferents (1, 2). The most recent advances, intercomparison of spectroscopic techniques, and status of available laser sources are summarized in a recent review (3). Furthermore, photoacoustic (PA) spectroscopy is seen to be well suited for optical absorption measurements because it combines high sensitivity with the ruggedness needed for field-deployable instrumentation. However, laser PA spectroscopy (L-PAS) requires multihundredmilliwatt-level laser sources to achieve a sub-parts-per-billion (sub-ppb) level of sensitivity for many of the environmentally and industrially important gases. As a result, heretofore most of the sensitive L-PAS detection schemes have used continuouswave (CW) molecular gas lasers (4). Results and DiscussionHigh-Power Continuously Tunable Laser Source. The tuning characteristics of our high-power single-frequency source are seen in Fig. 1, which shows the single-mode laser power available from the CW room temperature (RT) external grating cavity (EGC) quantum cascade laser (QCL) (near 6.3 m) at several grating settings. Fig. 1 also shows the overall tuning of the output that covers Ͼ350 nm with CW RT laser power in excess of Ϸ200 mW with maximum CW RT laser power of 300 mW near the center of the tuning curve. Details are given in Materials and Methods.PA Spectroscopy of NO2. We have used the broadly and continuously tunable, high-power CW RT EGC-QCL source for PA spectroscopy of NO 2 , which exhibits strong absorption features near Ϸ1,600 cm Ϫ1 . NO 2 is a smog and particulate matter precursor and one of the key pollutants that is routinely monitored. Ambient concentrations of NO 2 typically are in single digits to tens of parts per billion (ppb) levels (5). The national ambient air quality standard (NAAQS) level for NO 2 is 53 ppb for arithmetic mean average (6). Consequently, an acceptable ambient NO 2 sensor should have single-digit ppb or, better, sub-ppb, sensitivity. Earlier, cryogenically cooled lead salt lasers (7) operat...

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Section: Methodsmentioning

confidence: 99%

Sub-parts-per-billion level detection of NO ₂ using room-temperature quantum cascade lasers

Pushkarsky

Tsekoun

Dunayevskiy

et al. 2006

Proc. Natl. Acad. Sci. U.S.A.

122

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“…Instead, we here consider the static model of the grating feedback and some stable and unstable features of the dynamics are presented. The effective reflectivity of the static model in grating feedback including the laser facet and the grating mirror with multiple reflections is calculated in the same manner as the conventional mirror in (4.25) and is given by (Binder et al 1990;Genty et al 2000)…”

Section: Feedback From a Grating Mirrormentioning

confidence: 99%

Theory of Optical Feedback in Semiconductor Lasers

Ohtsubo

2012

Springer Series in Optical Sciences

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A semiconductor laser with optical feedback is an excellent model for generating chaos in its output power and the system has proven to be very useful in practical applications. This chapter concerns the theoretical background for instability and chaos induced by optical feedback in narrow-stripe edge-emitting semiconductor lasers, such as Pabry-Perot lasers, multi-quantum well (MQW) lasers, and distributed feedback (DFB) lasers. Particular dynamics of feedback-induced instability and chaos in semiconductor lasers are separately discussed in the following chapter. In this chapter, we focus on the theoretical treatment of optical feedback effects in semiconductor lasers. Lasers show the same or similar dynamics as far as rate equations are described by the same equations. We here assume single mode operations for semiconductor lasers. The dynamics for multimode cases will be discussed in

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“…The second section is a fiber of length L ext , and the third is the FBG with This configuration may be conveniently analyzed as a simple two-mirror laser structure (Fig. 1b) by replacing the FP diode laser output facet reflectivity R o by a complexvalued effective reflection coefficient R eff [24][25][26][27][45][46][47].…”

Section: Fiber Grating Fabry-perot Laser Modelmentioning

confidence: 99%

Optimizing the external optical cavity parameters for performance improvement of a fiber grating Fabry–Perot laser

Hisham

Abas

Mahdiraji

et al. 2015

Opt Rev

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The effects of the external optical cavity parameters (external optical cavity length (L ext ), amplitude coupling (C o ) and anti-reflection coating (ARC) reflectivity coefficients) on the noise and modulation spectra of a fiber grating Fabry-Perot laser are numerically analyzed for designing a laser that operates in strong feedback regime (Regime V). Fiber Bragg grating (FBG) is used as a wavelength selective element to control the properties of the laser output by controlling the external optical feedback (OFB) level. The study is performed by modifying a set of rate equations that are solved by considering the effects of external OFB and ambient temperature (T) variations. We proposed a model to calculate the temperature dependence (TD) of laser characteristics according to the TD of laser parameters. An accurate analytical expression for the TD of threshold carrier density (N th,fe ) has been derived. The TD of N th,fe was calculated according to the TD of laser cavity parameters instead of using well-known empirical Pankove relationship via the use of characteristics temperature (T o ) and current (I o ). Results show that the optimum external fiber length (L ext ) is 3.1 cm. Also, it is shown that ARC with reflectivity value of 1 9 10 -2 is sufficient for the laser to operate at low noise, good modulation response, and low fabrication complexity.

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Analysis of the linewidth of a grating-feedback GaAlAs laser

Cited by 30 publications

References 22 publications

Sub-parts-per-billion level detection of NO ₂ using room-temperature quantum cascade lasers

Sub-parts-per-billion level detection of NO ₂ using room-temperature quantum cascade lasers

Theory of Optical Feedback in Semiconductor Lasers

Optimizing the external optical cavity parameters for performance improvement of a fiber grating Fabry–Perot laser

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Analysis of the linewidth of a grating-feedback GaAlAs laser

Cited by 30 publications

References 22 publications

Sub-parts-per-billion level detection of NO 2 using room-temperature quantum cascade lasers

Sub-parts-per-billion level detection of NO 2 using room-temperature quantum cascade lasers

Theory of Optical Feedback in Semiconductor Lasers

Optimizing the external optical cavity parameters for performance improvement of a fiber grating Fabry–Perot laser

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Sub-parts-per-billion level detection of NO ₂ using room-temperature quantum cascade lasers

Sub-parts-per-billion level detection of NO ₂ using room-temperature quantum cascade lasers