Joseph F. Ahadian

BIT-enabled VCSEL-based parallel optic transceivers

We present technology that enables high-resolution optical time domain reflectometer (OTDR) within aerospace transceivers. Transceivers with built-in-test (BIT) OTDR can characterize the fiber plant and isolate faults among the multiple fiber segments within the aerospace vehicles: at the board level, backplane level, or within multiple bulkhead links throughout the airframe. BIT OTDR has been proposed for improving reliability and reducing maintenance costs on aerospace platforms.

Harsh environment transceivers for the post-module ERA

In summary, VCSEL-based transceivers can be fabricated as compact embeddable components. VCSELs are available with 25 Gbps data rates per channel and are the lowest power optical components available (due to low lasing thresholds and uncooled operation).

Silicon-on-sapphire fiber optic transceiver technology for space applications

We present Single Event Upset (SEU) testing of a parallel fiber optic transceiver designed for communicating data using commercial Fibre Channel and GbE protocols at data rates up to 2.5 Gbps per channel (on eight parallel channels). This transceiver was developed for aircraft applications, such as the Joint Strike Fighter (JSF), Raptor and F/A-18 aircraft, that deploy fiber optic networks using multi-mode fiber operating at 850 nm wavelength. However, this transceiver may also have applications in space environments. This paper describes the underlying transceiver component technology, which utilizes complementary metal-oxide semiconductor (CMOS) silicon-onsapphire circuitry and GaAs VCSEL and PIN devices. We also present results of SEU testing of this transceiver using heavy ions at Brookhaven National Labs.

Film for enhanced operation in avionic fiber connector interfaces

We describe the use of an end-face film to enhance optical coupling, reduce required spring force, and protect the fiber end-faces in MT-based connector systems. We present analytical and experimental results using a 25 micron film on 50-micron graded index fibers in an MPO connector.

Individual thermal control and in situ optical monitoring for optoelectronic component burn-in, qualification and reliability testing

We present a system burning-in, qualifying and reliability photonic components individual thermal control each device under and performs during We present the application of this to VCSEL-based parallel fiber for aerospace applications.

Chip-scale-packaging applied to optical transceivers

We discuss the application chip-scale packaging to create compact transceivers. Low-cost is achieve with wafer-scale packaging and a minimum sub-component count. These small solderable components offer increased density and PCB placement flexibility for optical interconnects.

Multi-mode fiber optic repeater

We demonstrate the capability of restoring high speed optical data signals after experiencing bandwidth and attenuation impediments that represent aircraft MMF cable plant.

Packaging technology for embedded optical modules

We present packaging technology for creating compact, high-data rate fiber optic components that are compatible with high-temperature operation and solder reflow board assembly. We describe the application of this technology for mid-board optical communications.

VCSEL-based RF photonics over multimode fiber

We present the evaluation of VCSEL-based RF photonic components. Research in low SWAP/Cost components is a relatively new field in RF photonics (previous work targets high-end performance, mainly centered on achieving high SFDR but at high SWAP/cost). The measured performance would support typical antenna remoting or RF signal distribution applications. The clearest applications are those requiring extreme isolation, low-phase noise, compact size, low power consumption, multiple-independent channels and/or flexible cabling. These applications arise in both military and commercial markets. We specifically examined the RF transmission needs for GPS user-equipment (UE) and identified the benefits from the use of VCSEL-based RF links.

Broken aerospace fiber optic cable characterization

This paper describes the physical and optical characterization of a fleet/field representative 100/140/172 (core/cladding/polyimide coating) aerospace fiber optic cable that failed due to cable bending/kinking.