Wavelength-switchable and multi-pulse bound state based on a hybrid mode-locked mechanism.

Relying on the nonlinear multimode interference in multimode fibers and the nonlinear polarization rotation, these two mode-locked techniques are combined in our proposed fiber laser. Stable optical soliton and multi-pulse regimes with a constant frequency of 11.44 MHz have been generated experimentally. Through altering intra-cavity conditions, bound-state pulses with diverse properties are observed. To the best of our knowledge, the obtained bound-state pulse constituted by more than thirty sub-pulses is achieved for the first time. Moreover, the center wavelength of bound-state pulse could be switched in a certain range covering the entire C band.

Evolutions of Q-switched mode-locked square noise-like pulse with different cavity lengths.

A $Q$-switched mode-locked square noise-like pulse (QMLSNLP) is generated in a nonlinear polarization rotation passively mode-locked fiber laser. When the pump power changes from 154 mW to 414 mW, the frequency of the $Q$-switched envelope varies from 21.7 kHz to 38.9 kHz, while the duration of the $Q$-switched envelope decreases from $5.1\,\,{\unicode{x00B5}\rm s}$ to $3.2{\unicode{x00B5}\rm s}$, correspondingly. In the meantime, QMLSNLP keeps the fundamental repetition rate constant, and the pulse duration increases from 3.4 ns to 6.7 ns. By inserting different lengths of single-mode fiber into the ring cavity, the evolutions of QMLSNLP are measured and analyzed. According to the cavity parameters and experimental results, impacts of the cavity length on QMLSNLP are investigated in detail.

[Application of computer assisted navigation in the treatment of unilateral zygomatic complex fractures].

OBJECTIVE: To evaluate the effect of computer assisted navigation system in the treatment of unilateral zygomatic complex fractures. METHODS: Five patients with unilateral zygomatic complex fractures were included in this study.Preoperative design, intraoperative real-time navigation and postoperative evaluation with chromatogram were executed in the unaffected and affected side. RESULTS: Using computer assisted navigation system, the position and direction of the affected side of the unilateral zygomatic complex fracture were confirmed and shown real-time on the screen. The global maximal deviation was less than 2 mm between the affected side and the mirror side of the healthy side with chromatogram. CONCLUSIONS: Computer assisted navigation system can instruct the treatment of unilateral zygomatic complex fractures effectively. The global comparison with chromatogram is more objective for the unilateral zygomatic complex fractures.

[Permeability research of human temporomandibular joint disc and cartilage].

OBJECTIVE: To measure the permeability of human temporomandibular joint (TMJ) disc and cartilage to provide basic parameter for oral biomechanics and tissue engineering, and analyze its mechanisms of pathology and load-release. METHODS: Confined compression method was used to measure the permeability (k value) of four cadavers' TMJs, which were sampled into three parts: disc, condyle and glenoid fossa with different diameters (2 mm, 3 mm and 4 mm). All 128 samples were tested with correspond diameter indenter. RESULTS: Larger the sample diameter was, higher the k value became. The highest k value appeared in the disc while the lowest appeared in glenoid fossa. CONCLUSION: In normal condition, TMJ can suffer huge load by decreasing its permeability. Disc is weakest for the higher permeability, it's easy-damaged region is an initiated factor of TMJ disease.