Prototypes for Laser and LED Applications

The prototype engineering group develops prototypes and models making UV LEDs and diode lasers usable in specific application fields.

PLS - tailored, flexible picosecond light impulse sources

Picosecond pulse laser system PLS 1000
Picosecond pulse laser system PLS 1000
picosecond pulse laser source PLS 1030
all-in-one picosecond pulse laser source PLS 1030

With its PLS series, the FBH offers very efficient, pulsed laser sources combining in-house developed optical and electronic semiconductor components. The laser system is currently being optimized in a way that all functionalities are integrated in just one compact device, instead of so far two separate components, offering improved capability in addition. This all-in-one PLS 1030 delivers ultra-short light impulses at a wavelength of 1030 nm within an adjustable time range from 5 to 15 ps and provides freely selectable repetition frequencies, from the hertz to the megahertz range. Pulse peak performance is at more than 20 watts. Due to these properties, the laser source is ideally suited for application in materials processing, especially in connection with fiber amplifiers, for biomedical examinations based on fluorescence spectroscopy, and for mobile LIDAR systems.

The all-in-one device can be equipped with semiconductor components for 1030 nm and 1064 nm, but can be flexibly transferred to other wavelengths. It consists of a mode-locked laser with around 4 GHz repetition rate, an innovative pulse picker element, and an optical amplifier. Electronic control has also been developed by the institute using FBH gallium nitride transistors. As a result, short impulses can be flexibly selected from single to multiple serial pulses (burst mode) and amplified. All-in-one PLS 1030 is computer-operated in order to easily integrate it into various laser systems, thus ensuring stable and user-friendly operation.

UV-B LED module
UV-B LED module for triggering the biosynthesis of secondary metabolites in plants
UV-C LED module
UV-C LED module for sterilizing cell-carrier fluid in flow cytometry
UV-C LED module
Rod-shaped UV-C LED module for water disinfection developed by the FBH (top: water supply, left: cooling)

UV-B module for plant growth lighting

This module allows the irradiation of a defined area with UV-B light of specific wavelength. UV-B LEDs offer a narrow emission spectrum, and their peak-wavelength can be tailored to ideally match the effective spectrum. This UV-B module can, for example, be used to optimize the biosynthesis of specific natural plant substances. It can additionally be supplemented with red and blue LEDs - their irradiation intensity can be adjusted indepently from each other. This setup ensures an optimum test procedure of LED lighting used in plant growth research.

UV-C module for fluid disinfection in flow

This module allows to disinfect low amounts of slowly flowing liquids by irradiation with UV-C LEDs. It is therefore particularly suited as point-of-use device for sterilizing, e.g., cell-carrier fluid in flow cytometry. The peak-wavelength can be tailored to obtain the most-effective germ-inactivation rate. Depending on the LED power, the quantity of flowing water to be disinfected is currently limited to 10-20 ml/min.


UV-C LED module for water disinfection in flow-through reactors

FBH has designed a rod-shaped module for water disinfection purposes using in-house developed 262 nm LEDs. This module aims at replacing conventional low-pressure mercury vapor lamps. UV LEDs score with higher lifetimes and are maintenance-free. Since they do not require toxic chemicals like mercury they are environmentally friendly in addition – mercury lamps need to be disposed safely after a few 1,000 hours operation. Wavelength and emission characteristics can also be adjusted specifically to the desired application. FBH’s demonstrator utilizes 40 LEDs each delivering an optical output power of 1.7 mW; the medium irradiation intensity at a distance of around 2 cm is at approximately 2.0 W/m2. The geometry follows conventional flow-through water disinfection reactors, for example, for treatment of drinking or process water. This FBH setup is modularly expandable and can thus be adapted to various reactor sizes. Two LEDs form an assembly group with a constant current supply (max. 100 mA per LED) and a temperature termination for security reasons. Heat is dissipated via a heat pipe with attached fan.