Abstract: A heat assisted magnetic recording (HAMR) writer is described. The HAMR writer includes a laser, a polarization rotation plate and a HAMR transducer. The laser provides energy having a first polarization state. The polarization rotation is plate optically coupled with the laser and changes the first polarization state to a second polarization state. The transducer has an ABS, a waveguide, a main pole, at least one coil and a near-field transducer (NFT). The polarization rotation plate is between the transducer and the laser. The waveguide is optically coupled with the laser through the polarization rotation plate and directs the energy from the polarization rotation plate toward the ABS. The NFT focuses the energy onto a media. The NFT is optically coupled with the waveguide and receives energy having a third polarization state. The main pole writes to the media and is energized by the coil(s).

Abstract: A transmit optical subassembly (TOSA) includes a spot-size-converted (SSC) semiconductor laser coupled to an optical fiber without a lens or isolator. The spot-size-converted semiconductor laser includes an active region and an expander region that expands the spot size of the laser while maintaining efficient active laser performance. The SSC laser is coupled to a submount and passively aligned to an optical fiber positioned within a V-shaped groove formed within the submount. The SSC laser includes a narrow far field advantageous for providing a high coupling efficiency and high quality data transmission. The SSC laser is resistant to back reflection and produces a 1.3 or 1.55 micron optical wavelength and a data rate ranging from 1 to 10 Gbps. The TOSA provides high coupled power due to narrow far field, with potential extra reflection resistance due to absorption and mode transfer losses in coupling reflections through the expander back into the active region.

Abstract: The optical transmitter/receiver apparatus of the invention includes: an optical fiber for transmitting/receiving an optical signal therethrough; and a first base including mutually spaced optical signal transmitting and receiving regions and a fiber end supporting region located between the optical signal transmitting and receiving regions. A semiconductor laser device for emitting the optical signal to be transmitted is secured to the optical signal transmitting region of the first base. A fiber end supporting portion for supporting one end of the optical fiber, to which the optical signal emitted from the semiconductor laser device is incident, is formed in the fiber end supporting region of the first base. A second base for supporting the body of the optical fiber is secured to the optical signal receiving region of the first base.

Abstract: The optical device of the present invention includes a substrate, at least one first groove formed on the substrate, an optical fiber placed in the first groove, and at least one second groove diagonally formed across the optical fiber. Furthermore, the optical device includes an optical member inserted in the second groove, having a surface which reflects or diffracts at least a part of light propagating through the optical fiber. A photodetector is placed at a position where light which is reflected or diffracted by the optical member is received. As a result, an miniaturized optical device having a low loss and high reliability can be provided at low cost.

Abstract: The optical transmitter/receiver apparatus of the invention includes: an optical fiber for transmitting/receiving an optical signal therethrough; and a first base including mutually spaced optical signal transmitting and receiving regions and a fiber end supporting region located between the optical signal transmitting and receiving regions. A semiconductor laser device for emitting the optical signal to be transmitted is secured to the optical signal transmitting region of the first base. A fiber end supporting portion for supporting one end of the optical fiber, to which the optical signal emitted from the semiconductor laser device is incident, is formed in the fiber end supporting region of the first base. A second base for supporting the body of the optical fiber is secured to the optical signal receiving region of the first base.

Abstract: The optical transmitter/receiver apparatus of the invention includes: an optical fiber for transmitting/receiving an optical signal therethrough; and a first base including mutually spaced optical signal transmitting and receiving regions and a fiber end supporting region located between the optical signal transmitting and receiving regions. A semiconductor laser device for emitting the optical signal to be transmitted is secured to the optical signal transmitting region of the first base. A fiber end supporting portion for supporting one end of the optical fiber, to which the optical signal emitted from the semiconductor laser device is incident, is formed in the fiber end supporting region of the first base. A second base for supporting the body of the optical fiber is secured to the optical signal receiving region of the first base.

Abstract: A first pumping beam at a wavelength of 1210 nm emitted from a first pumping source is focused by a first lens system on an optical fiber. A second pumping beam at a wavelength of 650 nm emitted from a second pumping source passes through a coupler and a second lens system and arrives at the optical fiber to be incident thereon. Tm ions with which a core portion of the optical fiber is doped sequentially experience a ground-state level absorption transition upon absorption of the first pumping beam, an excited-state level absorption transition to an upper laser level upon absorption of the second pumping beam, and a radiative transition from the upper laser level to a ground-state level, thereby emitting light at a wavelength of 460 to 500 nm. The light at a wavelength of 460 to 500 nm emitted from the Tm ions is resonated by a resonator consisting of an incident mirror and an emitting mirror and outputted as a laser beam.

Abstract: The optical fiber is doped at the core thereof with Tm ions and Nd ions. When light at a wavelength in a 800-nm band for exciting the Nd ions, is incident upon the optical fiber through an incident portion thereof, the Nd ions emit light at a wavelength in the vicinity of 1,012 .mu.m. Through three excitations by absorption of light emitted from the Nd ions and/or energy transfer from the Nd ions, the Tm ions experience three excitation transitions and reach a third high energy level through first and second high energy levels. Thereafter, the Tm ions experience a radiative transition from the third high energy level, thereby to emit blue light at a wavelength of 480 nm.

Abstract: The effective rate of deactivation from the terminal state to the ground state of a rare earth ion doped optical material in a four-level amplifying or lasing scheme may be increased greatly by doping the optical material with two rare earth ions, an activator and a deactivator. Energy transfer occurs between the terminal state in the activator ion and the deactivator ion. The transition from the deactivator to the ground state occurs via phonon emission. By increasing the deactivation rate, the efficiency of the laser and the amplifier is increased.

Abstract: A core of a fluorozirconate optical fiber is doped with rare earth ions, namely trivalent Dy ions. The Dy ion makes an absorption transition with excitation light generated by an 800 nm semiconductor laser module. Then the Dy ion undergoes transitions, namely a nonradiative transition involving phonon emission, a transition to a metastable excited level, and a radiative transition wherein radiation corresponding to the 1.28 .mu.m to 1.35 .mu.m range occurs, thereafter returning to its ground state level. The Dy ion having an electrovalence of three can be pumped with a high-output 800 nm semiconductor laser module and is not subject to saturation at a lower energy level of population inversion. Using an optical fiber of the invention, a higher gain is obtained in the region of 1.3 .mu.m telecommunications window.