Research News 2018

FBH research: 18.12.2018

Substrate mode suppression for an InP MMIC process

FBH has developed an InP MMIC process in which epitaxial layers are transferred from comparably fragile InP wafers to robust Si host wafers. Implementing through-silicon vias and wafer thinning are straightforward parts of the procedure, this process is now available as standard module to suppress substrate modes at highest frequencies.

FBH research: 02.10.2018

Bidirectional GaN HFETs for T-type converter power conversion

Power switching transistors are used in switch mode power supplies for power conversion - most of them carry current and have to block voltage in only one direction. GaN transistors from the FBH can be operated in both directions and thus enable particularly efficient T-type converters.

FBH research: 05.09.2018

Elaborate assembly technology for tunable diode lasers

The FBH develops sophisticated tunable diode lasers based on a MOPA concept, e.g. for frequency conversion applications. It has identified the most effective mounting and assembling process to couple the seed laser light efficiently over several lenses into the amplifier chip.

FBH research: 21.08.2018

Dual-wavelength diode lasers with adjustable wavelength distance

FBH is developing tunable diode lasers emitting at two individually adjustable wavelengths that separate, among others, wanted Raman from unwanted background signals. These laser sources are required for applications like absorption or Raman spectroscopy, THz frequency generation, and non-linear frequency conversion.

FBH research: 09.07.2018

Chalmers GaN HEMT Charge Model – Revisited

The Chalmers model is one of the frequently used and well-known GaN HEMT models, featuring two implementations of capacitive effects: the capitance and the charge-based model. To achieve more precise results, both model parameters have been thoroughly analyzed.

FBH research: 09.05.2018

Optimized electron blocking layer for UV-B light emitting diodes

(In)AlGaN-based UV-B LEDs are promising candidates to replace established UV light sources in various applications. However, high defect densities in these materials, among others, limit their efficiency. The FBH has therefore studied the influence of EBL doping and EBL material composition on the emission power of 310 nm LEDs.

FBH research: 24.04.2018

GaN HEMT-based THz detectors

The FBH develops highly sensitive, fast-response and broadband THz detectors for CW and pulsed operation. Since fast THz cameras with high sensitivity are mandatory for many industrial applications, FBH is also working on focal plane arrays of THz detectors to transfer the excellent single detector performance to a THz camera.

FBH research: 11.04.2018

γ-irradiation tests of volume-holographic Bragg gratings

Spaceborne quantum optical sensors for high-precision measurements rely on compact and robust narrow linewidth laser systems. The radiation hardness of the VHBGs which enhance the frequency stability of the employed laser modules was shown by FBH for typical low-earth-orbit conditions.