RESUMO
Major life changes may cause an autobiographical rupture and a need to work on one's narrative identity. This article introduces a new qualitative interview methodology originally developed to facilitate 10 prostate cancer patients and five spouses in the (re)creation of their life narratives in the context of a series of interventive interviews conducted over a timespan of several months. In "The Clip Approach" the interviewees' words, phrases, and metaphors are reflected back in a physical form ("the Clips") as visual artifacts that allow the interviewees to re-enter and re-consider their experience and life and re-construct their narratives concerning them. Honoring the interviewees as authors facilitates autobiographical reasoning, building a bridge between the past and the future, and embedding the illness experience as part of one's life narrative. The Clip Approach provides new tools for both research and practice-potentially even a low-threshold psychosocial support method for various applicability areas.
Assuntos
Narração , Resolução de Problemas , Humanos , Masculino , Instrumentos CirúrgicosRESUMO
New laser methods have introduced new possibilities and partly replaced traditional methods in corneal surgery. Femtosecond lasers have traditionally been used to replace the surgeons' knife in corneal refractive surgery and corneal transplantation. Excimer laser has been used from the beginning of 1990 for the reshaping of cornea. With the development of excimer laser, traditional photorefractive corneal surgery has improved and new methods have been found such as PRK, PTK, epi-LASIK, and LASEK. Today LASIK, the most commonly used refractive surgery, uses both femtosecond and excimer lasers. SMILE, the most recent method in corneal refractive surgery, is solely based on the use of femtosecond laser.
Assuntos
Cirurgia da Córnea a Laser/métodos , Cirurgia da Córnea a Laser/instrumentação , HumanosRESUMO
We demonstrate 1.5 W of output power at the wavelength of 750 nm by intracavity frequency doubling a wafer-fused semiconductor disk laser diode-pumped at 980 nm. An optical-to-optical efficiency of 8.3% was achieved using a bismuth borate crystal. The wavelength of the doubled emission could be tuned from 720 to 764 nm with an intracavity birefringent plate. The beam quality parameter M2 of the laser output was measured to be below 1.5 at all pump powers. The laser is a promising tool for biomedical applications that can take advantage of the large penetration depth of light in tissue in the 700-800 nm spectral range.
Assuntos
Lasers , Fenômenos Ópticos , SemicondutoresRESUMO
We report for the first time on the performance of 1300 nm waveband semiconductor disc lasers (SDLs) with wafer fused gain mirrors that implement intracavity diamond and flip-chip heat dissipation schemes based on the same gain material. With a new type of gain mirror structure, maximum output power values reach 7.1 W with intracavity diamond gain mirrors and 5.6 W with flip-chip gain mirrors, using a pump spot diameter of 300 µm, exhibiting a beam quality factor M(2)< 1.25 in the full operation range. These results confirm previously published theoretical modeling of these types of SDLs.
Assuntos
Lasers Semicondutores , Luz , Eletricidade , Luminescência , Refratometria , Análise EspectralRESUMO
We present 6.1 W of output power from a flip-chip semiconductor disk laser (SDL) emitting in the 1.3 µm wavelength region. This is the first demonstration of a flip-chip SDL in this wavelength range with output powers that are comparable to those obtained with intracavity diamond heat spreaders. The flip-chip configuration circumvents the optical distortions and losses that the intracavity diamond heat spreaders can introduce into the laser cavity. This is essential for several key applications of SDLs.
RESUMO
A proof-of-principle study of a 1.97-µm Tm:Lu2O3 ceramic disk laser, intracavity pumped by a 1.2-µm semiconductor disk laser, is presented. The demonstrated concept allows for improved pump absorption and takes advantage of the broad wavelength coverage provided by semiconductor disk laser technology. For thin disk lasers the small thickness of the gain element typically leads to inefficient pump light absorption. This problem is usually solved by using a complex multi-pass pump arrangement. In this study we address this challenge with a new laser concept of an intracavity pumped ceramic thin disk laser. The output power at 1.97 µm was limited to 250 mW due to heat spreader-less mounting scheme of the ceramic gain disk.
RESUMO
We report the first (to our knowledge) wafer-fused high-power passively mode-locked semiconductor disk laser operating at 1.57 microm wavelength. An InP-based active medium was fused with GaAs/AlGaAs distributed Bragg reflector on a 2 inch wafer level, resulting in an integrated monolithic gain mirror. An intracavity wedged diamond heat-spreader capillary bonded to the gain chip provides efficient heat removal from the gain structure without disturbing the spectrum of the mode-locked laser. The laser produces over 0.6 W of average output power at 15 degrees C with 16 ps pulse width. The total output power accounting for all output beams emerging from the cavity was 0.86 W. The results reveal an essential advantage of wafer fusion processing of disparate materials over monolithically grown InP-based gain structures and demonstrate the high potential of this technique for power scaling of long-wavelength semiconductor disk lasers.
RESUMO
We report on bistable mode-locking in a semiconductor disk laser. The disk laser mode-locked with a semiconductor saturable absorber is investigated for different designs of the gain medium that allow the hysteresis loop to be controlled. Hysteresis formation in the pulsed regime of a semiconductor oscillator with saturable absorption and unsaturated gain is discussed qualitatively. The laser represents an attractive setup for generation and manipulation of dissipative solitons and observation of their interaction.
RESUMO
We report on optically-pumped vertical-external-cavity surface-emitting lasers passively mode-locked with a semiconductor saturable-absorber mirror. The potential of harmonic mode-locking in producing pulse trains at multigigahertz repetition rates has been explored. The results present first systematic study of multiple pulse formation in passively mode-locked VECSELs.
RESUMO
We report on power scaling of optically-pumped semiconductor disk lasers using multiple gain scheme. The method allows for significant power improvement while preserving good beam quality. Total power of over 8 W was achieved in dual-gain configuration, while one-gain lasers could produce separately about 4 W, limited by the thermal rollover of the output characteristics. The results show that reduced thermal load to a gain element in a dual-gain cavity allows extending the range of usable pump powers boosting the laser output.
RESUMO
Comments on the comments made by Brown et al. (see record 2013-24609-001). The article by Brown et al. regarding the Fredrickson and Losada (see record 2005-11834-001) article discussed the use of differential equations in science and repeated our earlier observation (Luoma, Hämäläinen, & Saarinen, 2008) that there is lack of justification for the use of the Lorenz equations in the latter article. In this comment we want to point out that Brown et al. presented a very narrow view on mathematical modeling in behavioral research. We describe how the conceptual use of mathematical models is essential in many fields.