Abstract: A device for adjusting laser diodes includes a pilot signal adjustment device for adjusting the signal current using a pilot signal frequency that is modulated onto the signal current. The device includes a bias direct current source supplying the laser diode with a bias direct current. A switching device switches the adjustment device between a state where the pilot signal adjustment device is connected to the modulator and the bias direct current source such that the signal current can be adjusted using the pilot signal adjustment device, and another state where the modulator is connected to the temperature compensation device such that the signal flow can be adjusted and/or controlled by the temperature compensation device.

Abstract: The present invention is an optical turn used to the monitor the output of a light source such as a VCSEL. Light incoming to the optical turn is reflected off of a totally internally reflecting surface towards a window-mirror, where the light is partially routed to an output lens, and partially diverted to a monitor lens where the diverted light can be focused onto a monitoring device, such as a photodiode. In an alternative embodiment of the present invention, the optical turn is modified to monitor an incoming light array. In another alternative embodiment, the optical turn monitors an incoming light array, and further includes a zigzag multiplexer that is used to carry out Coarse Wavelength Division Multiplexing (CWDM). CWDM is the combination of different wavelengths of light into one beam.

Abstract: Active element for a laser source and laser source comprising such an active element. According to the invention, the active element for a laser source comprises an elongate rod comprising a doped matrix capable of absorbing a pump beam in order to amplify laser radiation propagating longitudinally, at least one input face for the pump beam, a first reflection face for the pump beam which is inclined with respect to the longitudinal axis of the rod and at least one interacting second reflection face, at least one of the input face and second reflection face being equally inclined.

Abstract: A wavelength tunable semiconductor vertical cavity surface emitting laser which includes at least one active element including an active layer generating an optical gain by injection of a current, and at least one phase control element, and mirrors. The phase control element contains a modulator exhibiting a strong narrow optical absorption peak on a short wavelength side from the wavelength of the laser generation. The wavelength control is realized by using a position-dependent electro-optical effect. If a reverse bias is applied, the absorption maximum is shifted to longer wavelengths due to the Stark effect. If a forward bias is applied, a current is injected and results in the bleaching and reduction of the peak absorption. In both cases a strong modulation of the refractive index in the phase control element occurs. The effect tunes the wavelength of the cavity mode, and the sign and the value of the wavelength shift are defined by the position of the modulator.

Abstract: In annealing a non-single crystal silicon film through the use of a linear laser beam emitted by a YAG laser of a light source, it is the object of the present invention to prevent heterogeneity in energy caused by an optical interference produced in the linear laser beam from having an effect on the silicon film. The laser beam is divided by a mirror 604 shaped like steps into laser beams which have an optical path difference larger than the coherence length of the laser beam between them. The divided laser beams are converged on an irradiate surface 611 by the action of a cylindrical lens array 605 and a cylindrical lens 606 to homogenize the energy of the laser beam in the length direction and to determine the length of the linear laser beam.

Abstract: In a laser drive circuit for use in an optical disc recording and reproducing apparatus, a P-channel MOS transistor acting as a drive current source generates a drive current ILD depending on a setting current Ic. A P-channel MOS transistor acting as a current switch supplies the drive current ILD to a semiconductor laser, in response to a drive pulse signal CP. An OP amplifier controls a setting current Ic depending on a monitor current Im and a setting voltage Vc. A capacitor removes noise generated by the transistor acting as a current switch and superposed on the drive current ILD.