Distributed feedback diode

For TOLAS measurement in PEMFCs, the laser diode as the transmitter and the photodiode as the detector are used. In a typical experimental setup with TOLAS as Basu et al. reported, the laser beam from the distributed feedback diode (DFB) laser at a wavelength of 1470 nm was split using a bifurcated optical fiber. One leg... 

With die system described above, a section of the C2H2 overtone spectrum around 1512 nm has been measured, using a distributed feedback diode laser. The noise equivalent absorption coefficient is in the order of 5x10 cm or a detection limit of less than 100 ppb... 

Determination of the branching ratio for the product channels in reaction of CH3COOH with OH radicals in a smog chamber under atmospheric conditions by measuring the CO2 formation yield (CW-CRDS using a distributed feedback diode laser at 1570 nm) is in progress. 

Fig. 11. Schematic of edge-emitting laser diodes where the arrows represent the direction of laser emission and U represents the active region (a) standard stmcture with cleaved facets for mirrors and (b) distributed feedback (DFB) laser that employs coherent reflection from a grating to generate optical...

Details of the laser system and the operating conditions employed to control the lasers have been described previously [6]. The system includes two independently operated distributed feedback (DFB) InGaAsP diode lasers tuned over the desired transitions near 1.34 p,m and 1.39 p,m i/ + I s bands)... 

Figure 10.4 High-resolution absorption spectrum of propane near 1.68 /xm measured by temperature-tuning a distributed feedback (DFB) diode laser Ptotai = 1 atm and T =...

Although many diode lasers work as multimode lasers, the distributed feedback (DFB) and distributed Bragg reflector (DBR) lasers show a mode selection because of their periodic structure. The mode selectivity is generated by the optical properties of the periodic stmctures because (Mily the modes that are associated with a standing wave/stop band are amplified. DFB structures are photonic structures, which are doped throughout the volume with chromophores (in an optimal case at the maxima of the standing waves), whereas DBR lasers have a miniature Fabry-Perot cavity in which the dye is localized, and the mirrors are replaced by periodic gratings [85]. 

DFB (distributed feedback) laser Laser diode in which light feedback for oscillation is realized by diffraction grating. 

Special laser chip structures can be designed in which a kind of diffraction grating is incorporated into the laser structure itself. These lasers are called distributed-feedback (DFB) lasers. DFB laser diodes... 

FIGURE 9.42 Semiconductor diode laser using a distributed feedback cavity. 

Cooper DE, Martinelli RU, Carlisle CB, Riris H, Bour DB, Menna RJ (1993) Measurement of 12C02 13C02 ratios for medical diagnostics with 1.6-iJ,m distributed-feedback semiconductor diode lasers. Appl Opt 32 6727-6731 Dakin JP, Edwards HO, Weigl BH (1995) Progress with optical gas sensors using correlation spectroscopy. Sens Actuators B 29 87-93... 

The resonance characteristics of the RR were measured through the wavelength modulation of a distributed feedback laser diode by sweeping the injection current. ... 

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