Bernard Orsal

Correlation between electrical and optical photocurrent noises in semiconductor laser diodes

The low and medium frequency (1 Hz/spl les/f/spl les/10 MHz) electrical noise characteristics of 0.98, 1.3, and 1.55 micrometer semiconductor lasers have been investigated. We show that the electrical noise is connected to the optical noise behavior. The correlation between electrical and optical noises is obtained by using the coherence function between these noise sources. This confirms the theoretical predictions issued from Haugs model that this correlation, which originates in the dipole interaction between the optical field and electron-hole pairs, can be extended to the laser diode characterization by using electrical noise measurements. >

Strongly sub-Poissonian electrical noise in 1.55-/spl mu/m DBR tunable laser diodes

We report terminal electrical noise measurements on 1.55-/spl mu/m DBR tunable laser diodes in the 1 Hz-1 MHz frequency range, performed using an electrical correlation method. These measurements are compared with a comprehensive electrical model based on rate equation formalism. Taking into account diffusion phenomenon and structural parameters, we obtain a complete agreement between the model and the measurements above threshold and a quite similar tendency below threshold. The influence of Bragg section bias is also discussed.

Electrical and optical noise of high power strained quantum well lasers used in Erbium doped fiber amplifiers

The optical amplifiers are formed by an Erbium‐doped fiber, optically pumped medium by a high power semiconductor laser emitting in the 980 nm region. The pump power is efficiently injected into the Erbium fiber using a precision wavelength division multiplexing fiber optic coupler. The aim of this paper is to propose a noise study of InGaAs/GaAs ridge single quantum well (SQW) lasers as pump lasers.

Low-frequency noise measurements as an investigation tool of pixel flickering in cooled Hg/sub 0.7/Cd/sub 0.3/Te focal plane arrays

We report on electrical noise measurements on both Hg/sub 0.7/Cd/sub 0.3/Te test patterns and hybrid 320 /spl times/ 256 focal plane array in order to explain the low-frequency pixel flickering physical origin. Dark and under infrared illumination test patterns characterization highlights that the detector chip is not responsible for the flickering phenomenon. Taking into account the silicon readout chip influence when the full infrared complementary metal-oxyd semiconductor (IRCMOS) infrared detector is investigated, the indium bump based interconnecting system is finally pointed out as a potential excess noise source.

About the physical origin of pixel flickering in cooled Hg0.7Cd0.3Te infrared photodetectors

We report on electrical noise measurements on both Hg0.7Cd0.3Te test patterns and hybrid 320 × 256 focal plane array in order to explain the low frequency pixel flickering physical origin. Dark and under infrared illumination test patterns characterization highlights that the detector chip isn’t responsible for the flickering phenomenon. Taking into account the silicon readout chip influence when the full IRCMOS infrared detector is investigated, the indium bump based interconnecting system is finally pointed out as a potential excess noise source.

Low and Medium Frequency Noise Levels of fibered very‐high‐power 1460nm‐Pump Laser Diode designed for Raman Amplification

We report low and medium frequency optical noise measurements on very‐high‐power fibered 1460nm‐Pump Lasers (P > 200mW) designed for Raman Amplification. These Fabry‐Perot Lasers exhibit spectra from a quite monomode situation (Side Mode Suppression Ratio ≈ 10dB) at near threshold current injection (Ithreshold ≈ 28mA) up to very multimode spectra (5nm Full Width at Half Magnitude) at very high biases (ILaser ≈ 1000mA). In this paper, we have to focus on two main things : on one hand, the low and medium frequency noise behavior of the laser itself and on the other hand the measurement data post‐treatment.

Analysis of the optical noise behavior of a LiNbO3 electro-optic modulator

The optical noise of the set: DFB Laser + EOM has been investigated, in a medium frequency range. This noise characterization clearly shows that in most cases the modulator increases the noise level properly relevant to the laser emitter. However, far above threshold, the optical noise at the end of the modulator tends, in some specific cases, to the fundamental noise, that is to say the shot noise level.

Noise of 980-nm InGaAs/GaAs strained quantum-well lasers and correlation with aging

The longitudinal mode hopping and the related terminal electrical noise in InGaAs/GaAs ridge single quantum well (SQW) lasers are investigated. It is found that electrical mode hopping has a Lorentzian dependence. The correlation with the optical noise is experimentally shown for low and medium frequencies.