A comprehensive model for the photon number fluctuations and the current noise in quantum cascade lasers is presented. It is shown that the photon intensity noise in quantum cascade lasers exhibits little amplitude squeezing even when noise in the drive current is suppressed below the shot noise value. This is in contrast to interband semiconductor diode lasers in which the laser intensity nois...

Selective area molecular beam epitaxial regrowth of Ino.aGaesAs lasers through dielectric masks between GaAs laser stripes on a GaAs substrate has been used for the -first timeto monolithically integrate these two lasers emitting near 1.0 and O.&S pm, respectively. During regrowth, GaAs laser stripes were protected under a dielectric mask over which polycrystalline material grew, which was late...

A substantial reduction is reported in the threshold current densities for 1 5 p m wavelength In,Ga,+,As/ In,Ga, .,As, -”P, strained-layer multiple quantum well (SLMQW) lasers over lattice-matched MQW lasers. Threshold current density was found to depend sensitively on the InAs content x and thickness d of the In,Ga, -.As quantum wells. Threshold current densities as low as 370A/cm2 and interna...

An investigation is performed of the possibility of achieving simultaneous distributed strain and temperature sensing based on hybrid Raman–Brillouin scattering with the use of multi-wavelength optical sources such as common Fabry–Perot (FP) lasers. By employing a self-heterodyne detection scheme based on a multi-wavelength optical local oscillator, the benefits of FP lasers are fully exploited...

Relative timing jitter between synchronized Q-switched lasers, or lack thereof, is important for stable sum-frequency generation. Experimental investigation of two passively synchronized lasers shows that the jitter is minimized when the free-running repetition rates of the two lasers are close to, but not exactly, matching. When the free-running repetition rates are matched, the jitter is sign...

Q-switched lasers are prevalent in applications that require high intensity laser in ultra short pulses. For many medical applications of Q-switched lasers, it is crucial to have smooth and controlled pulse shapes [1, 2]. In dermatological applications, for instance, an irregular shape or duration of a laser pulse during pigmentation removal can cause serious damage to the surrounding healthy t...

Low-power lasers are a group of lasers with a power less than 250 mW and unlike high-power lasers they have no effect on tissue temperature; they produce light-dependent chemical reactions in tissues. These lasers have analgesic features with their ability to trigger reactions that reduce pain and inflammatory mediators. Low-power lasers can also be used instead of needles in acupuncture to dec...

We demonstrate a frequency comb (FC) swept laser and a frequency comb Fourier domain mode locked (FC-FDML) laser for applications in optical coherence tomography (OCT). The fiber-based FC swept lasers operate at a sweep rate of 1kHz and 120kHz, respectively over a 135nm tuning range centered at 1310nm with average output powers of 50mW. A 25GHz free spectral range frequency comb filter in the s...