Abstract: A p-type InP buffer layer containing Zn in a low concentration and an undoped InP buffer layer having a carrier concentration of 3×1017 cm?3 or less are stacked on a p-type InP substrate containing Zn. On the undoped InP buffer layer, a Mg-doped p-type InP cladding layer, an InGaAsP optical confinement layer, an InGaAsP MQW active layer, an n-type InGaAsP optical confinement layer, and an n-type InP cladding layer are successively stacked. The diffusion of Zn from the p-type InP substrate into the InGaAsP MQW active layer is suppressed. Moreover, a steep doping profile can be formed in the vicinity of the active layer so that deterioration of device characteristics is suppressed.

Abstract: A frequency-stabilized laser source that is adapted for use as a frequency standard. The frequency of the laser source is locked and the laser beam delivered by the laser source on a transition of an absorber chemical element. The technique combines both operation with saturated absorption and synchronous detection, based on modulating said transition being saturated by the beam passing through the absorber chemical element. This produces a single frequency laser beam whose output frequency is stationary. The frequency is not continuously modulated and is more precise than that which would be obtained operating with single-pass absorption only. The laser source is thus adapted for making a frequency standard.

Abstract: In order to achieve a long wavelength, 1.3 micron or above, VCSEL or other semiconductor laser, layers of strained quantum well material are supported by mechanical stabilizers which are nearly lattice matched with the GaAs substrate, or lattice mismatched in the opposite direction from the quantum well material; to allow the use of ordinary deposition materials and procedures. By interspersing thin, unstrained layers of e.g. gallium arsenide in the quantum well between the strained layers of e.g. InGaAs, the GaAs layers act as mechanical stabilizers keeping the InGaAs layers thin enough to prevent lattice relaxation of the InGaAs quantum well material. Through selection of the thickness and width of the mechanical stabilizers and strained quantum well layers in the quantum well, 1.3 micron and above wavelength lasing is achieved with use of high efficiency AlGaAs mirrors and standard gallium arsenide substrates.

Abstract: Method and arrangement are disclosed for a power distribution network for distributing power to VCSELS on an optoelectronic chip that maintains a constant bias voltage to the VCSELs. More particularly, the power distribution network includes an H-tree network for directing a power signal. The H-tree network includes a primary input for receiving the power signal and at least one level, with terminal nodes coupled to the last level, and each level includes a plurality of segments. Each segment of a respective level is equal in length and the total number of segments from the primary input to each terminal node is the same. Since the distance from the primary input to each terminal node is equal, greater bias voltage uniformity is provided to the terminal nodes. A similar distribution network is used for the ground connection.

Abstract: A position and adjustment device for a laser module has a cylindrical body having a bore therein, the body having a first plurality of openings and a second plurality of openings that are spaced apart around the body. A laser module is positioned inside the bore. The position and adjustment device also has a plurality of bolts, with each bolt extending through a corresponding one of the first openings into the bore, each bolt having an inner end and a rotating ball provided at the inner end and providing a rolling contact with the external surface of the laser module. The position and adjustment device also has a plurality of biased pins, with each pin extending through a corresponding one of the second plurality of openings into the bore, each pin having a curved inner end that provides a point contact with the external surface of the laser module.

Abstract: An optical fiber that transmits laser beams generated by a laser diode in an optical module is provided with a fiber grating. The fiber grating passes most of the laser beams and reflects some of them to a photodiode provided on the back side of the laser diode. The photodiode also receives scattered laser beams from the laser diode. The photodiode outputs a current equivalent to the amount of received laser beams. An APC circuit controls emission of laser beams by the laser diode based on this current.

Abstract: A beam parameter monitoring unit for coupling with a molecular fluorine (F2) or ArF laser resonator that produces an output beam having a wavelength below 200 nm includes a detector and a beam path enclosure. The unit may also include a beam splitter within the enclosure for separating the output beam into first and second components, or first and second beam are attained by other means. The detector measures at least one optical parameter of the second component of the output beam. The beam path enclosure includes one or more ports for purging the beam path enclosure with an inert gas to maintain the enclosure substantially free of sub-200 nm photoabsorbing species.

Abstract: The invention is related to an optical device having a housing (1) with a defined gas atmosphere. The housing includes a wavelength monitor, for monitoring an optical signal The wavelength monitor includes an etalon (2) with a gap between two etalon plates. The optical device also has a laser diode and means for influencing the temperature (3) of the laser diode. The optical device further includes special means to influence the gas density in the gap between the etalon plates.

Abstract: A solid-state light source apparatus includes a first excitation laser light source for outputting a laser beam of a first wavelength, a second excitation laser light source for outputting a laser beam of a second wavelength, a difference frequency between the laser beam of the first wavelength and the laser beam of the second wavelength being in a terahertz band, and a semiconductor pseudo phase matching device which is disposed at a place where a first optical axis of the laser beam of the first wavelength overlaps with a second optical axis of the laser beam of the second wavelength, and generates a terahertz beam in a direction coaxial with the first and second optical axes on the basis of irradiation of the laser beams of the first and second wavelengths. Thus, high output and high efficiency terahertz wave generation can be easily and certainly realized while a narrow line width characteristic is maintained.