Three-dimensional photonic waveguide devices are fabricated in glass by use of femtosecond pulses from an extended-cavity laser oscillator. Three-dimensional devices, including a symmetric three-waveguide directional coupler and a three-dimensional microring resonator, are fabricated and tested. Waveguides can be fabricated at depths of approximately 1 mm inside a glass substrate, thus demonstrating the capability of achieving dramatic increases in device density. These results demonstrate the potential to fabricate new classes of devices that are not possible in two dimensions.

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We demonstrate and characterize symmetric [3x3] three-dimensional directional couplers fabricated in glass using a high-pulse energy femtosecond laser oscillator. The characteristics of the [3x3] directional couplers closely agree with the theoretical prediction, except for small errors caused by the fabrication process. We show that deviations from symmetry are dominated by vertical position errors of the coupling waveguide.

In a randomized, double blind, placebo controlled study; the acceptability, efficacy and safety of injectable midazolam as oral premedicant in children was evaluated. One hundred children (ASA 1,2) aged 6 months to 6 years, undergoing elective neurosurgical operations, like meningomyelocele, meningo-encephalocele, ventriculo peritoneal and other shunts and craniotomies for tumour decompression etc., were included in the study. The patients were randomly assigned to one of four groups (A, B, C, D) receiving respectively saline or 0.50, 0.75 and 1.0 mg/kg midazolam in honey, 45 min before separation from parents. All received identical general anesthesia (GA). Age, sex, weight, heart rate, blood pressure, respiratory rate, saturation (SaO2), reaction to parent's separation, sedation score and duration of anesthesia, recovery conditions and side effects were noted. We found no difference in age, sex, weight, patient acceptability vomiting after ingestion and duration of anesthesia between groups. Even though many children resisted the placement of premedicant in the mouth, only three children spat it out and none vomited after swallowing. The reaction to separation from parents was better after midazolam premedication. However, on reaching the operating room, 24% children (placebo-60%) were found anxious after 0.50 mg/kg, but 12% were deeply sedated after a dose of 1.0 mg/kg. Recovery was similar in groups A, B and C except that more (48%) patients were anxious in group A. Recovery, however was delayed in 16% patients of group D. Though, fewer complications were reported during recovery after midazolam than placebo premedication, they were minimal in the 0.75 mg/kg group. We concluded that giving injectable midazolam orally as premedication in pediatric age group scheduled for neurosurgical operations is acceptable, effective and safe in 0.75 mg/kg dose. While 0.50 mg/kg is less effective, 1.0 mg/kg does not offer any additional benefit over 0.75 mg/kg but does delay recovery and may compromise safety.