Here we present the physics and device characteristics of high performance strain-compensated MOCVD-grown 1200 nm InGaAs and 1300–1400 nm InGaAsN quantum well (QW) lasers. Utilizing the GaAsP barriers surrounding the highly strained InGaAsN QW active regions, high performance QW lasers have been realized from 1170 nm up to 1400 nm wavelength regions. The design of the InGaAsN QW active region u...

For the first time to our knowledge we experimentally demonstrate an efficient method for the reduction of long-term radiation line drift in single-frequency cw Ti:sapphire and dye lasers that relies on a fast and precise wavelengthmeter together with a digital-analog feedback system. Generation line drift of lasers is reduced approximately by an order of magnitude down to 40 MHz/h, which corre...

We have developed a theory that unifies the analysis of the modal properties of surface-emitting chirped circular grating lasers. This theory is based on solving the resonance conditions which involve two types of reflectivities of chirped circular gratings. This approach is shown to be in agreement with previous derivations which use the characteristic equations. Utilizing this unified analysi...

Lasers were introduced into the field of clinical dentistry with the hope of overcoming some of the drawbacks posed by the conventional methods of dental procedures. Since its first experiment for dental application in the 1960s, the use of laser has increased rapidly in the last couple of decades. At present, wide varieties of procedures are carried out using lasers. The aim of this review is ...

A model for the photon noise and the current noise in quantum cascade lasers is presented. It is shown that compared to diode lasers quantum cascade lasers exhibit much less photon-number squeezing even when the noise in the drive current is suppressed well below the shot-noise value. The theoretical model presented in this paper self-consistently accounts for the suppression of the current noi...

Two types of the dual mode-locked fiber lasers for asynchronous absolute distance measurement are investigated. The lasers are linear and ring cavity with repetition rate of 70 MHz and 100 MHz, respectively. The group velocity dispersion is not compensated in the first type of the lasers, while the others are fully done. The timing jitter with the Allan deviation below averaging time of 0.2 s d...

Lasers and LEDS Electrical to optical video converters generally have a BNC coaxial cable connector at the input and a fiber optic connector on the output. In order to get the digital bits down the fiber optic cable, a light emitting device is used, onto which the digital signal is modulated. Either a laser or an LED (Light Emitting Diode) is used for this purpose. Lasers are more expensive, bu...

Low-threshold, gain switched colloidal quantum dot (CQD) distributed-feedback lasers operating in the nanosecond regime are reported and proposed for sensing applications for the first time to the authors' knowledge. The lasers are based on a mechanically-flexible polymeric, second order grating structure overcoated with a thin-film of CQD/PMMA composite. The threshold fluence of the resulting ...

Medicinal lasers are a standard source of light to produce retinal tissue photocoagulation to treat retinovascular disease. The Diabetic Retinopathy Study and the Early Treatment Diabetic Retinopathy Study were large randomized clinical trials that have shown beneficial effect of retinal laser photocoagulation in diabetic retinopathy and have dictated the standard of care for decades. However, ...