NEW Case Study: Active Ring Resonators Using Mid-Infrared QCLs

Ring resonators are one of the most versatile building blocks of photonic integrated circuits (PICs). They have contributed to scaling down optical laboratory experiments and making commercial technologies more portable. The PIC world is growing in applicability and physically shrinking in size, and it can enable reduction of global electricity consumption, improved classical and quantum optical signal processors, and lightweight and cost-effective devices for spectroscopy.

Researchers in Massachusetts, Austria, and Portugal have designed an active mid-infrared ring resonator incorporating a quantum cascade active region in the waveguide core with directional couplers. The resonance frequency, quality factor, and coupling regime and coefficients can all be tuned electrically to better fit multiple applications. By changing these parameters, the active ring resonator can act as a tunable filter, a nonlinear frequency converter, or a frequency comb generator. This design allows active ring resonator integration into the mid-infrared spectral region (3-12 μm) for a variety of applications in photonic integrated circuits with significant power output of 10 mW for spectroscopy, communication, and microwave generation.

It was critical to have precise control of the drive current as the probe wavelength was tuned by ramping the injection current. The racetrack quantum cascade laser (QCL) operation state is highly dependent on the injection current especially when dealing with frequency comb generation.

All laser devices, including a Fabry-Perot QCL, were driven with Wavelength Electronics’ low-noise current drivers QCL1500 LAB or QCL2000 LAB and their temperature was stabilized at 16ºC using Wavelength Electronics’ low thermal drift temperature controller TC5 LAB. The high performance and precision of Wavelength Electronics provided the necessary stability of the laser sources in the active mid-IR ring resonators.

The complete case study is available as CS-LDTC14.

Introducing Bryan Livergood, Applications Engineer

Bryan is a graduate in Electrical Engineering from Montana State University and brings over 20 years of experience in electronics. The majority of his career has been in the medical industry.

He comes to us from Big Sky Medical Center, where he served as a Clinical Engineer. Prior to that role, he was an Engineering Supervisor at Xtant Medical.

Bryan is here to assist with any technical needs you may have.

Contact Bryan.

NEW VIDEO: WTC32ND-14 Temperature Controller Mini-Instrument Quick Start

The WTC32ND-14 is a mini-instrument temperature controller with a temperature display and onboard adjustments. Wrapped around the precision WTC32ND temperature controller, it is configured for use with a TCS610 10 kΩ thermistor and various thermoelectrics driving up to ±2.2 Amps.

The controller is particularly suited to applications where temperature is scanned across ambient, such as electro-optical systems, LIDAR, Raman spectroscopy, and medical diagnostic equipment.

Watch the video

NEW Case Study: Quantification of the Removal and Inactivation of Virus Particles

Researchers from the Netherlands have developed and demonstrated a new method of quantifying and characterizing antiviral properties of polymer-functionalized surfaces for virus filtration and inactivation. Specifically, a polyethylenimine (PEI)-coated poly(ether sulfone) (PES) micro-filtration membrane was used to adsorb, inactivate, as well as disassemble virus capsids. Using fluorescence microscopy, spectroscopy, and single particle counting, only a small fraction (1%) of intact viruses can pass through the membrane, and a large fraction of viruses became inactivated and disassembled. Not only does the virus adsorb onto the PEI coating, it also interacts with PEI to disassemble the virus capsid. This new method provides a simpler and faster quantification and characterization technique for virus filtration and inactivation in the medical and biological world.

In this single particle counting design with fluorescence microscopy, researchers benefited from Wavelength Electronics’ laser diode driver, LD5CHA, with worry-free setup and easy integration. The LD5CHA enabled precise current control of the laser diode with minimal electronic noise from the driver. As noise could contribute to any false positive readings, lower electrical noise may lead to better spectra recordings and data analysis. The peak fluorescence wavelength red- or blue-shifted by ~3 nm for intact or disassembled virus particles, and the laser driver ensured narrow linewidth from the laser diode for precise detection of the fluorescence spectra.

The complete case study is available as CS-LD10.

NEW Case Study: Determining Localized Density of H2O2 Using Absorption Spectroscopy in Plasma Jets

Researchers from Germany have developed and demonstrated a new diagnostic technique for obtaining local distribution of gas phase hydrogen peroxide (H2O2) in plasma jets. Continuous-wave cavity ringdown spectroscopy, with a quantum cascade laser at a wavelength of 8.12 μm, is used to determine the effective absorption length of a cold atmospheric pressure plasma jet and to determine the localized density of H2O2 in the effluent of the plasma jet. With axial and radial scans and radial distributions, the effective absorption length was calculated to be 1.6 mm close to the nozzle and 5 mm at a distance of 10 mm from the nozzle.

The maximum density of H2O2 was found in the center of the effluent close to the nozzle. This work shows the formation and consumption mechanisms of H2O2 and enables other biomedically relevant species in the plasma zone to be studied using this technique.

Measuring the localized density of H2O2 with high-accuracy requires high precision and stable control of the quantum cascade laser when using continuous-wave cavity ringdown spectroscopy (cw-CRDS). Wavelength Electronics’ QCL driver, QCL1000 OEM, enabled precise current control with minimal electronic noise from the QCL. As laser linewidth is a major concern for QCLs, the QCL1000 OEM minimizes noise for open air measurements to as low as 0.7 μA up to 100kHz as well as keeping the average current noise density to as low as 2 nA / √Hz.

The stability of the QCL temperature is also critical for consistent wavelength output from the QCL. Wavelengths’ PTC5K-CH temperature controller, can precisely stabilize temperature to as low as 0.0012ºC. The PTC utilizes a PI controller to minimize overshoot and time to reach setpoint temperature. The stability that the QCL driver and PTC controller provided for the QCL made the 3,600 repeatable measurements more reliable.

The complete case study is available as CS-LDTC13.

PROMOTION: Test Drive Any Instrument for 30 Days FREE

We are sure that once you experience the precision, stability and ease-of-use of our touchscreen instruments, you’ll be convinced that they are ideal for your high performance application. We are offering a year-end promotion to test drive any instrument for 30 days for free.

Choose a TC LAB precision temperature controller with Intellitune®, a LDTC LAB laser driver with temperature control, or our patented, low noise QCL LAB.

Available for North American deliveries only.

Start your test drive.

Wavelength Electronics’ 30th Anniversary

WAVELENGTH ELECTRONICS CELEBRATES 30 YEARS

Wavelength Electronics turned 30 in October! Since 1993, Wavelength Electronics has solved electronics problems in photonics systems from our factory in Bozeman, Montana. We started with driving laser diodes and controlling their temperatures. Our first products were OEM modules and components that laser engineers could design into their own systems. The vision was to provide benchtop instrument performance in a small package.

We’ve maintained our focus on LD safety and evolved to offering only high-performance solutions – very stable current, very low noise, very stable wavelength through temperature stabilities limited only by sensor precision.

We’re committed to researching new technologies as they emerge, and constantly expanding our capabilities. At present, our CW laser diode drivers can modulate in the MHz range. We can scale the output currents to support VCSELs at the low end and pump diodes at the high end. Our temperature controllers easily achieve mK stability – regardless of environmental conditions. We offer both linear and higher efficiency PWM output stages.

We have chosen to focus on high performance. Our customers leverage our expertise to gain a competitive advantage and develop solutions that significantly improve lives.

We believe a design is only finished when it can be manufactured repeatedly with high yield. In addition to our knowledge of circuitry, we researched best-in-class electronics manufacturing practices. We’ve invested in automated production equipment – two SMT lines, a selective solder, AOI. We’ve developed procedures and protocols in our Quality System to consistently achieve a return rate of less than 0.1%. From our humble beginnings with plate-through resistors, we’ve embraced building with the smallest of SMT components – 0201s, BGAs. We also offer our assembly services to local companies. Our team members pride themselves on finding improvements, integrating new technologies, and contributing to our clients’ success.

Where are we going? Eventually we will be able to drive any semiconductor laser made in all operating modes.

For now, we are introducing Custom Engineering Services. Custom circuit designs that perfectly fit the system need – multiple channels, compact size, any combination of form fit and function. Learn More.

NEW Case Study: VCSEL Absorption Spectroscopy of Chip-scale Rubidium Atomic Vapor

Researchers from the Indian Space Research Organization in Bengaluru, India have developed and demonstrated the absorption spectroscopic capabilities of a chip-scale Rubidium (Rb) atomic vapor cell using a thermoelectric cooler integrated VCSEL light source in a magneto-optic package. The custom 3D-printed design provides real time analysis of spectral data. With over 600 hours of data, absorption resonance lines were recorded and analyzed for transitions 85Rb and 87Rb with absorption amplitude and FWHM data agreeing with known literature values.

For the compactness and wavelength stability of the design, both the size and stability of the temperature controller are critical in the success of the absorption spectroscopy study. The VCSEL diode required high temperature stability due to the center frequency shifting with change in temperature. To meet these requirements, researchers used Wavelength Electronics’ WTC3243 Temperature Controller.

This magneto-optic Rb atomic cell package proves potential for atomic sensors, particularly in space borne applications or payloads.

The complete case study is available as CS-TC08.

NEW Case Study: Dual-Comb and Fourier Transform for Fast and High Spectral Spectroscopy

Complex chemical and biological reactions require fast (sub-second) spectroscopy with high spectral resolution. Researchers from Switzerland have developed a Fourier Transform (FT) spectrometer designed around a custom, continuous rotation scanning mirror, enabling millisecond acquisition times while maintaining high spectral resolution in the sub-GHz range. The demonstrated system incorporates the advantages of both FT spectroscopy as well as dual-comb spectroscopy. This design not only uses a single frequency comb for dual-comb spectroscopy, but can prove useful in a variety of spectroscopy applications where high speed, large optical bandwidth, and high spectral resolution are desired.

Combining FT spectroscopy with dual-comb spectroscopy for fast acquisition and high-spectral resolution requires high precision and stable control of the quantum cascade laser. Wavelength Electronics’ QCL1000 OEM driver enabled precise current control with minimal electronic noise. The driver also allows analog wavelength modulation of up to 2-3 MHz. This enabled laser tuning by changing the drive current to the QCL with a triangular current modulation ramp. As laser linewidth is a major concern for QCLs, the QCL1000 OEM minimizes noise to as low as 0.7 μA up to 100kHz as well as keeping the average current noise density to as low as 2 nA / √Hz.

Our QCL driver enables sub-second spectroscopy with high spectral resolution with low noise and stable laser output. This makes the developed rotational FT spectrometer system a reliable tool for dual-comb spectroscopy for applications in reaction and leakage monitoring and in-line process analytical technology.

The complete case study is available as CS-LD09.

Precision Temperature Control Instrument Now CE Certified

THE POPULAR LFI3751 INSTRUMENT NOW HAS WIDER APPLICABILITY

The LFI3751 high-performance Autotune PID temperature control instrument has been used for cell monitoring, PCR, cancer therapy, quantum systems, and medical/biochemical/materials research equipment.  Now, this powerful controller has been CE certified, enabling access to markets that accept and require CE-marked devices.

Use the LFI3751 to drive up to ±5A to either thermoelectrics or resistive heaters with up to 9.5V compliance. This instrument operates from AC (100-240V, 50 or 60Hz). Expect stability as good as 0.001°C with thermistors. Even across ambient, this PID controller maintains precision temperature.

From the front panel, adjust temperature limits, current limits, setpoint, PID control values, sensor calibration data, and enable or disable output current. The Analog model has an external analog setpoint input via BNC on the rear panel. The 4-digit display shows actual or setpoint temperature or resistance, output current and voltage.

Autotune PID is a sophisticated algorithm for optimizing the PID control parameters to your load. With the touch of a button, the LFI3751 automatically optimizes control settings for most thermal loads, reducing overshoot or improving temperature stability. Autoranging sensor bias currents keep your sensor voltage in the optimal range for maximum signal to noise ratio. It comes with Addressable RS232 and USB control is available with an adapter cable. Free LabVIEW drivers simplify computer control. Benchlink software simulates the front panel control from your PC. A Digital PID option provides better setpoint resolution and stability with low-resolution sensors such as RTDs. This option also offers improved overshoot suppression, 50% faster settling times, and faster calibration.