AlGaAs lasers

Fig. 9. High power array of phase coupled GaAs/AlGaAs lasers mounted -side down on a thermal heat sink. The tt/2 shift of the neighboring lasers is indicated by the + and — signs. The output pattern consists of two dominant peaks, each associated with the lasers of the same phase, and much weaker...

For applieation (see below) the ions are irradiated with a laser diode (Sect. 10.4) Er " absorbs 800 nm from an AlGaAs laser diode, Tm absorbs 650 nin from newly developped laser diodes. Ftgure 10.5 shows that the ion reaches the green-emitting level by subsequently absorbing two photons. Two different pathways are indicated their relative importance depends on the ratio of the different transition rates. Also the Tm ion reaches the blue emitting Dj and O4 levels by a two-step process. In both cases a quadratic dependence of emission intensity upon excitation power has been observed [6]. 

K. Kikuchi and T. Okoshi, Estimation of linewidth enhancement factor of AlGaAs lasers by correlation measurement between FM and AM noises, IEEE J. Quantum Electron. QE-21 669 (1985). 

Operation with laser diodes simply requires construction of a cell of the same configuration as above, but with the dielectric stack reflectivity centered to match that of the gold at the wavelength used. Thus we were able to demonstrate laser diode driven optical bistability using the AlGaAs laser output from a demounted compact disk player read arm (Fig. 3). The higher critical switch power of 62.5 /iW is due to the larger spot size of 117 //m ( /e diameter) used. 

Aluminum gaUium arsenide (AlGaAs) lasers NIR or visible (750-1,000 nm) From 10 mW up to 0.4 W (CW) Room temperature, low cost... 

GaAs/AlGaAs photocathodes, solar cells, lasers, HEMATs, high-power LEDs, MESFETs... 

Stripe—geometry gain—guided AlGaAs-GaAs quantum well heterostructure lasers have been fabricated from masked hydrogenation to produce the resistive regions necessary to current confinement. 

P. Zory and L. D. Comerfold, Grating-coupled double-heterostructure AlGaAs diode lasers, IEEE J. Quant. Electron QEll, 451-457 (1975). 

Lasers and LEDs. Dye lasers pumped by Ar ion, Cu ion and frequency doubled Nd YAG solid state lasers. LEDs operating at 635-652, diode lasers at 635 (AlGalnP), 652 (InGaAlP) and 730 mn (AlGaAs). Solid state pulsed lasers, (e.g. Nd YAG, Nd YLF) operating at second, third and fourth harmonic generation. 

For the continuous-wave semiconductor (AlGaAs) distributed feed back lasers (DFB) used in telecommunication technology today a nonlinear refractive index n2=S cm2/GW would be necessary for all-optical switching, which is presumably impossible to reach. Including an Erbium doped fiber amplifier (EDFA) the needed nonlinearity drops only by a factor of ten. 

---