Silicon waveguide infrared photodiodes with >35 GHz bandwidth and phototransistors with 50 AW-1 response.

SOI CMOS compatible Si waveguide photodetectors are made responsive from 1100 to 1750 nm by Si+ implantation and annealing. Photodiodes have a bandwidth of >35 GHz, an internal quantum efficiency of 0.5 to 10 AW-1, and leakage currents of 0.5 nA to 0.5 microA. Phototransistors have an optical response of 50 AW-1 with a bandwidth of 0.2 GHz. These properties are related to carrier mobilities in the implanted Si waveguide. These detectors exhibit low optical absorption requiring lengths from <0.3 mm to 3 mm to absorb 50% of the incoming light. However, the high bandwidth, high quantum efficiency, low leakage current, and potentially high fabrication yields, make these devices very competitive when compared to other detector technologies.

Incidence of cancer among patients with systemic sclerosis in Korea: results from a single centre.

OBJECTIVE: The aim of this study was to determine whether the incidence of cancer has increased among patients with systemic sclerosis (SSc) in Korea. METHODS: The study subjects consisted of 112 patients who had been consecutively evaluated for at least 6 months between 1990 and 2007. We retrospectively reviewed their medical records, investigated the incidence rate of cancer and compared it with that of the Korea National Cancer Centre database. RESULTS: Nine out of 112 patients developed cancer (four males and five females). The average age at diagnosis of cancer was 56.4 years and the mean disease duration was 8.9 years. The standardized incidence ratio (SIR) for SSc patients was 4.2 [95% confidence interval (CI) 2.3-6.1], 3.7 for women (95% CI 1.2-6.2) and 6.4 for men (95% CI 1.6-11.2). Lung cancer was the most common cancer (n = 4), followed by oesophagus (n = 1), stomach (n = 1), liver (n = 1), pancreas (n = 1), and squamous cell carcinoma of unknown origin (n = 1). All patients who developed lung cancer were female and non-small cell carcinoma in origin. The SIR of lung cancer in female patients was 23.0 (95% CI 6.0-40.0). Two out of four lung cancer patients had concomitant interstitial lung disease (ILD); all were non-smokers. Treatment agents, autoantibodies, smoking, and lung involvement were not significantly different between SSc patients with or without cancer. CONCLUSION: The SIR of cancer was significantly higher in SSc patients, and especially in those who were male, than in the general population. Lung cancer was the most common cancer. Active surveillance for the detection of cancer should be performed in all SSc patients.

CMOS-compatible dual-output silicon modulator for analog signal processing.

A broadband, Mach-Zehnder-interferometer based silicon optical modulator is demonstrated, with an electrical bandwidth of 26 GHz and V(pi)L of 4 V.cm. The design of this modulator does not require epitaxial overgrowth and is therefore simpler to fabricate than previous devices with similar performance.

All silicon infrared photodiodes: photo response and effects of processing temperature.

CMOS compatible infrared waveguide Si photodiodes are made responsive from 1100 to 1750 nm by Si(+) implantation and annealing. This article compares diodes fabricated using two annealing temperatures, 300 and 475 degrees C. 0.25-mm-long diodes annealed to 300 degrees C have a response to 1539 nm radiation of 0.1 A W-(-1) at a reverse bias of 5 V and 1.2 A W(-1) at 20 V. 3-mm-long diodes processed to 475 degrees C exhibited two states, L1 and L2, with photo responses of 0.3 +/-0.1 A W(-1) at 5 V and 0.7 +/-0.2 A W(-1) at 20 V for the L1 state and 0.5 +/-0.2 A W(-1) at 5 V and 4 to 20 A W(-1)-1 at 20 V for the L2 state. The diodes can be switched between L1 and L2. The bandwidths vary from 10 to 20 GHz. These diodes will generate electrical power from the incident radiation with efficiencies from 4 to 10 %.

The analysis of lacquer crack in the assessment of myopic choroidal neovascularization.

OBJECTIVE: The aim of this study was to clarify the characteristic findings in myopic choroidal neovascularization (CNV) and the relationship with lacquer crack (LC). METHODS: In all, 66 consecutive myopic CNV patients treated with photodynamic therapy and/or intravitreal anti-vascular endothelial growth factor injection in one eye were reviewed. Data from fluorescein angiography (FA) and indocyanine green angiography (ICGA), obtained simultaneously using the Heidelberg retina angiograph 2 (HRA2), were analyzed. RESULTS: LCs were associated with a relatively large extent (≥3000 µm) of peripapillary choroidal atrophy and a dark rim, the proliferation of retinal pigment epithelial cells surrounding the neovascular membrane was accompanied by a small extent. Myopic CNV usually developed in the LC area surrounded by tiny crack fragments. In all, 35 patients with LCs received FA and ICGA at least twice during follow-up. LC progression was observed in nine (25.7%) treated eyes and six (23.1%) non-CNV fellow eyes. Crack fragments progressed in three distinct forms such as elongation, branching, or bridging pattern. Newly diagnosed myopic CNV was reported in 18 treated eyes and 3 fellow eyes. Progression of LCs and development of CNV occurred simultaneously in eight eyes. By multivariate Cox's regression, a statistically significant association was observed between recurrence of myopic CNV and the absence of a dark rim on ICGA. CONCLUSIONS: The HRA2 instrument affords detailed high-resolution images of FA and ICGA. Notably, recurrence of myopic CNV developed in areas surrounded by new small crack fragments and LCs are considered to be important in the development of myopic CNV.