36 research outputs found
LASER-GAS SPECTROPHONE MEASUREMENTS WITH A FIBER-OPTIC INTERFEROMETER
Un interfĂ©romĂštre Ă fibre optique est utilisĂ© comme capteur acoustique dans un spectrophone Ă gaz. Une dĂ©tectivitĂ© de 1,6 x 10-7 cm-1·W/âHZ a Ă©tĂ© dĂ©montrĂ©e.A fiber-optic interferometer is the acoustic sensor in a gas spectrophone. A minimum detectable absorption capability of 1.6 x 10-7 cm-1·W/âHZ has been demonstrated
Distributed feedback gain-coupled lasers based on InGaAs quantum-wire arrays
Fabrication and characterization of a current-injected InGaAs-GaAs quantum-wire gain-coupled distributed feedback (DFB) laser operating at 77 K at a wavelength of 923 nm are presented, Threshold current densities in broad area lasers were measured to be as low as 160 A/cm(2), The side-mode suppression ratio at twice threshold is 35 dB. A 4-mu m rib waveguide device has a threshold of 14 mA, The patterning process for the second-order DFB grating fabricated with deep UV holography and wet-chemical etching is described