Ultra-high Q alumina optical microresonators in the UV and blue bands.

UV and visible photonics enable applications ranging from spectroscopic sensing to communication and quantum information processing. Photonics structures in these wavelength regimes, however, tend to experience higher loss than their IR counterpart. Particularly in the near-UV band, on-chip optical microresonators have not yet achieved a quality factor beyond 1 million. Here, we report ultra-low-loss photonic waveguides and resonators patterned from alumina thin films prepared by a highly scalable atomic layer deposition process. We demonstrate ultra high Q factor of 1.5×106 at 390 nm, a record value at UV bands, and 1.9×106 at 488.5 nm.

Treatment of a Patient With Meningioma With Complicated Blood Supply.

Meningiomas account for ~30% of primary intracranial tumors, making them the second most common type of brain tumor. Most meningiomas are benign, and surgical resection is curative. By utilizing 3-dimensional slicer technology for multimodal image fusion, a wealth of 3-dimensional anatomic information can be obtained, enabling more effective treatment of meningiomas with complex tumor locations and surrounding structures. Guided by the 3-dimensional structural models, we conducted detailed preoperative planning for 1 case of highly vascularized meningioma and utilized combined surgery for complete tumor removal, effectively avoiding intraoperative bleeding and postoperative complications.

Slit Ventricle Syndrome.

Slit ventricle syndrome (SVS) is a complication after ventriculoperitoneal shunt (VPS) or cystoperitoneal shunt(CPS), mostly due to excessive drainage of cerebrospinal. The disease is most often seen in children and has a complex pathogenesis. Clinical manifestations are mainly intermittent headache, slow refilling of the shunt reservoir, and slit-like ventricles on imaging. Surgery is the main treatment. We present a 22-year-old female patient with a previous 14-year history of CPS. The patient recently presented with typical symptoms but her ventricular morphology was normal. We performed VPS after diagnosis of SVS. After the surgery, the patient's symptoms improved and her condition was stable.

Intracranial Neuro-Enteric Cyst.

An intracranial nerve-enteric cyst is a relatively rare benign disease, and the main clinical manifestations are related to the location and size of the cyst. The main symptoms are caused by cyst compression. When the cyst is small without compression, it may have no obvious symptoms, and when the cyst increases to a certain degree, it may cause corresponding clinical manifestations. The diagnosis of this disease is mainly based on clinical manifestations, imaging examinations, and pathological examinations. The authors present a 47-year-old woman who was admitted to the hospital with "dizziness". Imaging was performed and revealed a small round lesion in the posterior cranial fossa in front of the brainstem. It was surgically removed and the postoperative pathology revealed an intracranial neuro-enteric cyst. The patient's dizziness disappeared after surgery and was reviewed 1 year later without recurrence.

Integrated photonic switches for nanosecond packet-switched optical wavelength conversion.

We present a multifunctional photonic switch that monolithically integrates an InGaAsP/InP quantum well electroabsorption modulator and an InGaAs photodiode as a part of an on-chip, InP optoelectronic circuit. The optical multifunctionality of the switch offers many configurations to allow for different optical network functions on a single chip. Here we experimentally demonstrate GHz-range optical wavelength-converting switching with only ~10 mW of absorbed input optical power, electronically controlled packet switching with a reconfiguration time of <2.5 ns, and optically controlled packet switching in <300 ps.

Dual-diode quantum-well modulator for C-band wavelength conversion and broadcasting.

We present a dual-diode, InGaAsP/InP quantum-well modulator that incorporates a monolithically-integrated, InGaAs photodiode as a part of its on-chip, InP optoelectronic circuit. We theoretically show that such a dual-diode modulator allows for wavelength conversion with 10-dB RF-extinction ratio using 7 mW absorbed optical power at 10 Gb/s. We experimentally demonstrate unlimited wavelength conversion across 45 nm between 1525 nm and 1570 nm, and dual-wavelength broadcasting over 20 nm between 1530 nm and 1565 nm, spanning the entire C-band with >10dB RF-extinction ratio and using 3.1-6.7 mW absorbed optical power at 1.25 Gb/s.