Conventional push-pull modulated (PPM) distributed feedback (DFB) lasers exploit structures with symmetry, which wastes a significant amount of the optical power output from rear facet. To improve efficiency, PPM DFB asymmetrically coated facets can be considered. However, resulted imbalanced modulation causes dip in device small-signal intensity response near carrier-photon resonance (CPR) fre...

We have developed a high-speed electroabsorption modulator integrated distributed feedback (EA/DFB) lasers. Transmission performance over 10 km was investigated under 25 Gbps and 43 Gbps modulation. In addition, the feasibility of wide temperature range operation was also investigated. An uncooled EA/DFB laser can contribute to the realization of low-power-consumption, small-footprint and coste...

Douglas-fir beetle (Dendroctonus pseudotsugae Hopkins) (DFB) causes considerable mortality to Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) in western North American forests. We evaluated the use of semiochemical-baited multiple-funnel traps for the protection of small, high-value stands of trees, such as those occurring in campgrounds, rest areas, and small parks when Douglas-fir mortalit...

This paper proposes an approach for acoustic emission (AE) source localization in a large marble stone using distributed feedback (DFB) fiber lasers. The aim of this study is to detect damage in structures such as those found in civil applications. The directional sensitivity of DFB fiber laser is investigated by calculating location coefficient using a method of digital signal analysis. In thi...

This report describes the results of a test of a new configuration of laser synthesizer for ALMA. The ALMA laser synthesizer is the source of the 1 LO photonic reference, in which a two-wavelength optical beatnote is transmitted by optical fiber from the ALMA AOS technical building to each of the array antennas. It is then used at the antenna as the reference for the first local oscillator, aft...

This is a continuation of our previous work [Opt. Express 16, 9155 (2008)]. In this paper we investigate the effect of nonuniform pumping on the modal properties of surface-emitting chirped circular grating lasers. By numerically solving the coupled-mode equations and matching the boundaries we compare and discuss the threshold pump levels and frequency detuning factors for three pumping profil...

We report the first experimental realization of four-channel DFB laser array with equivalent phase shift (EPS) based on the reconstruction-equivalent-chirp (REC) technique for CWDM systems. OCIS codes: (140.0140) Lasers and laser optics; (140.5960) Semiconductor lasers

Slope efficiency (SE) is an important performance metric for lasers. In conventional semiconductor lasers, SE can be optimized by careful designs of the facet (or the modulation for DFB lasers) dimension and surface. However, photonic wire lasers intrinsically suffer low SE due to their deep sub-wavelength emitting facets. Inspired by microwave engineering techniques, we show a novel method to ...

Distributed feedback (DFB) laser sensors with active films consisting of a highly efficient and photostable perylenediimide dye (perylene orange, PDI-O) dispersed in polysytrene (PS), used as passive matrix, are reported. PDIdoped-PS DFB lasers show an excellent operational durability under ambient conditions, superior to those of previously reported DFBs used for sensing purposes. Their bulk r...

Due to the piezoelectric properties of III–V materials, an acoustic wave propagating along the optical axis of a unipolar laser produces a periodic modulation of the carrier density and the optical gain, sufficient for providing distributed feedback ~DFB! with a mode suppression ratio exceeding 30 dB. In contrast to bipolar lasers, the piezoelectric modulation of unipolar carrier density is not...