16 entries, filtered by: Opto
Published: June 2011

XO035 is X-FAB’s specialized process for optoelectronic and high speed RF applications. It is especially suited for applications needing sensitive high bandwidth photo diodes arrays or CMOS image sensors for such applications as optical data storage, optical data communication or high dynamic range cameras.


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Published: May 2013

The filters are constituted by a Fabry-Perot resonator formed by two Bragg mirrors separated by a patterned cavity. The filter response can be tuned by changing the geometric parameters of the patterning, and consequently the cavity effective refractive index. In this way, many different filters can be produced at once on a single chip, allowing multichanneling. The filter has been designed, produced, and characterized. The results for a chip with 24 filters are presented.


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Published: December 2012

We present a method for producing monolithically integrated CMOS optical filters with different and customerspecific responses. The filters are constituted by a Fabry-Perot resonator formed by two Bragg mirrors separated by a patterned cavity. The filter response can be tuned by changing the geometric parameters of the patterning, and consequently the cavity effective refractive index. In this way, many different filters can be produced at once on a single chip, allowing multichanneling. The filter has been designed, produced, and characterized. The results for a chip with 24 filters are presented.


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Published: February 2012

PIN photodiodes are often used in optical integrated circuits. Although they can feature a very good RF-performance, this can be effected by the optical power density of the incident light. The influence of this effect on the RF-performance of PIN photodiodes is described. When a critical optical power density in the epi-layer is exceeded the 3dB frequencies are cut off. An analytical equation is derived to describe the effect. The results are compared to RF measurements and verified by numerical simulation.


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Published: September 2011

Diodes inherent in a CMOS process are light sensitive and could be exploited as photodetectors. To detect light the photo generated carriers need to be separated by the electrical field of an internal pn junction. They are either generated inside the depletion region or can get there by diffusion. The depth where these carriers are generated depends strongly on the wavelength. The generation profile, the pn junction depth and the diffusion length all impact the spectral sensitivity.


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Published: June 2011

Photo detector integrated circuits (PDIC) require high-sensitivity and high-bandwidth photo diodes for the latest generation of Blu-ray data storage devices. Due to the very short 405nm wavelength used, carriers are generated close to the surface. Standard photo diodes have only a low sensitivity for blue light. Therefore, special adapted photo diodes are necessary to support sensitivity higher than 0.25A/W for a 405nm wavelength.


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Published: April 2011

Silicon photodiode integrated with CMOS has been in extensive study for the past ten years due to its wide use in applications such as short-distance communication, VCD players, ambient light sensors and many other intelligent systems. In recent years, high speed blue-ray DVD is replacing conventional DVD due to its larger storage capacity and higher speed. In this work, the photodiode optimized for blue ray is fully integrated with standard 0.35um CMOS process and the bandwidth dependency upon thermal process and epitaxial material is investigated.


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Published: January 2011

Miniaturized video endoscopes with an imager located at the distal end and a simplified opto-mechanical layout are presented. They are based on a CMOS imager with 650 x 650 pixels of 2.8 μm pitch and provide straight view with 75° and 110° field of view at f/4.3. They have an outer diameter of 3 mm including the shell and a length of approx. 8 mm. The optics consist of polymer lenses in combination with a GRIN and a dispensed lens. Using a simple flip chip assembly, optical axis alignment better than 10 μm and a contrast of 30 % at 90 LP/mm was achieved. The 75° FOV system was sealed at the front window using a solderjetting technology, providing 10-9 mbar*l/s leakage rates even after several autoclave cycles.


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Published: January 2011

Visualization is still the most important tool in medical diagnostics to allow for the physician, in combination with their medical knowledge, to detect diseases within the human body and choose healing treatments in order to enable recovery. For minimal invasive surgical operations that use endoscopic tools, imaging camera modules that have both a small volume and a good resolution are necessary to ensure the success of the surgical treatment.
Microsystem technologies now allow for the direct integration of imaging optics and sensors in a system.


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Published: August 2009

Monolithically integrated photodiodes with high spectral responsivity over the entire visible and the near infrared spectral range are of growing interest for the semiconductor industry, since the next generation of optical data storage devices (Blue DVD) will soon be brought to market. In this paper, the bandwidth of photodiode dependence on the junction implant conditions and thermal budget was simulated by TCAD. It shows significant dependence on these process conditions. The corresponding mechanism related to RC delay, relationship between depletion region and light absorption will be discussed in detail with the help of simulation pictures and simple model explanation.


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