Zurich Instruments Newsletter - Edition Q1/2011
- A Cake with 3 Candles for Zurich Instruments
- Interview Jack Harris, Yale: Counterintuitive Behavior of Apparently Simple Systems
- Enlightening: Leaders join forces in Atomic Force Microscopy
- Innovative: New product HF2LI-PID Quad-PID Controller Option
- Flourishing: Publication Update
- Tips & Tricks: Maximum HF2 input and output voltages and currents
- Company Agenda
A Cake with 3 Candles for Zurich Instruments
With this issue, I would like to announce and celebrate a pleasant milestone. In April 2011 Zurich Instruments will have completed its third year of succesful operations having become a standard and reliable technology partner for many laboratories all over the world. Several customers in North America, Europe as well as in Asia have already purchased more than one instrument. This confirms that the HF2 platform provides the added value which people require for their setups. I am convinced that young companies such as Zurich Instruments have to focus on their customers, build relationships of trust, and rely on "word-of-mouth" as an effective promotion strategy. Since our date of inception we have dedicated all of our energies to create all that including a product culture that stands out from the crowd.
In the name of the ZI management team, I would like to thank all our customers for the trust put on us, and also for the countless recommendations that generate many interesting customer discussions. Further thanks go to our partners and supporters to make us proud of the daily achievements.
I would like hereafter to share a few statements collected over the past 3 years, "Incredibly good signal" a positive echo from Germany, "Keep up the good work" praise from Massachusetts, "Wow is all I can say!" an impressed scientist from California, "That's insane!" a memorable statement from a job applicant, "You guys are going to capture the market" a prophecy from the UK, as well as "It's truly amazing what you have accomplished" from Korea. My favorite however is "It appears that I do not have the full budget for your instrument. I either purchase the equipment for the post-doc or get rid of the post-doc to pay for the equipment".
Interview Jack Harris, Yale
Counterintuitive Behavior of Apparently Simple Systems
Hello Jack, your current projects are called radiation pressure and persistent current. Could you describe the essence of this research?
With the radiation pressure experiment (which we would actually rather call "optomechanics") we measure the interaction between MEMS oscillators and photons. The goal is to use this interaction to control both the MEMS and the photons on the quantum level. For the persistent current experiment, we are studying the ground state of metal rings. We are especially interested in the fact that this ground state can contain a dissipationless current, even though the ring is a resistor and not a superconductor.
Will these experiments influence our daily life in the future? How?
Optomechanics provides new ways of controlling MEMS with photons and vice versa. For example we have developed a novel type of interferometer that should make it possible to detect individual phonons (the quantum of the MEMS' motion). In addition, we are working on ways to use the MEMS to suppress the shot noise of a laser. These two projects should lead to more sensitive detectors of sound and light. The persistent current work is more focused on "basic" research, but we believe that persistent currents can tell us a lot about how conduction electrons interact with each other and their environment.
The internet lists 30+ publications of yours from the last decade. Could you mention 1-2 of your favorites?
I would say that my two favorites are the Science paper from 2009, which presented the most thorough study of persistent currents to date; and the Nature paper from 2008, which introduced our membrane-in-the-middle optomechanical device and illustrated its utility in strongly coupling photons to MEMS in a variety of different ways.
You have been working in Yale for the last 6 years. How has this environment influenced your research?
One of my favorite things about the environment here is the range of people thinking about connections between quantum optics, atomic molecular optics (AMO), and condensed matter systems. I am fortunate to have many inspiring colleagues in this area, both theorists and experimentalists. My research has been influenced by direct collaboration with them, and also by many informal discussions. It is a very supportive atmosphere for this type of research.
You are advancing into domains where it is very difficult to arrive at quantitative statements. What are tricks you apply to detect signals from noisy setups?
One of the most interesting signal processing schemes we are using should allow us to distinguish between a MEMS device's Brownian motion and its motion due to the quantum back action of a displacement measurement. This is a situation in which we are not so much trying to separate signal from noise, but rather "interesting" noise from "boring" noise. The basic scheme was invented by the optomechanics group at UPMC in Paris (led by Antoine Heidmann), and refined by our theory colleagues at Yale (Steve Girvin and Kjetil Børkje). The idea is to look for correlations between the MEMS' motion and the shot noise of laser light that has interacted with the MEMS.
What are the characteristics that you demand from the next generation oscillation instrumentation?
We are always interested in higher frequencies - a 500 MHz HF2 would be nice! Also, new means of tailoring the transfer functions of servo control loops would be great. For example it might be interesting to measure and implement complicated transfer functions (perhaps even nonlinear ones) with a single instrument.
Leaders join forces in Atomic Force Microscopy
Nanosurf, a leading provider of atomic force microscopes (AFM) and scanning tunneling microscopes (STM), and Zurich Instruments, technology leader for lock-in amplifiers and phase-locked loops (PLL), have announced a strategic technology partnership. The two companies have agreed to cooperate in the development of high-frequency, high-performance scanning probe microscopy (SPM) solutions, to provide mutual communication interfaces between their equipment, to share application know-how, and to perform joint promotion activities in key markets. In particular, Nanosurf will propose the Zurich Instruments high-performance 50 MHz PLL as upgrade path to its successful easyPLL and easyPLL plus platform, thereby granting Zurich Instruments immediate access to its large community of PLL users.
Nanosurf will continue to develop SPM controllers for its products, which will feature compatibility to Zurich Instruments PLLs for a seamless integration. Customers of Nanosurf will profit from known product performance and reliability, and - additionally - from the performance boost provided by Zurich Instruments technology.
New product HF2LI-PID Quad-PID Controller Option
The HF2LI-PID option builds on the HF2LI lock-in amplifier and seamlessly integrates no less than 4 high-performance PID (proportional integral derivative) controllers for general purpose control. The controllers provide the means to efficiently implement closed loop control on several physical parameters, such as demodulator outputs or auxiliary inputs.
The PID controllers are fully programmable for the 3 components, even if for most applications the proportional and the integration component are sufficient for control. In particular the PID units can be used preconfigured for automatic gain control (AGC) and Kelvin probe feedback (KPF). AGC has many applications in physics and engineering, whereas KPF is a dedicated, advanced atomic force microscopy (AFM) mode. One further application is for instance height control in AFM or in scanning near-field optical microscopy (SNOM). As the PID controllers can regulate on all demodulators outputs (amplitudes and phases), it is possible to regulate the physical parameters of many laboratory setups.
Users benefit from closed-loop bandwidth which is several orders of magnitude larger compared to implementations in LabVIEW. Better performance and less system noise are the consequence of of no external PID hardware. Overall this new option for the HF2LI lock-in amplifier provides an out-of-the-box closed-loop control solution: no programming required, and researchers can fully focus on their experiments rather than on the measurement infrastructure.
Zurich Instruments is proud to announce more than 10 publications that have been released with a direct reference to Zurich Instruments. Spreading into the academic and industrial communities, more and more groups present their results based on the measurements performed with Zurich Instruments products. For the updated list please have a look to www.zhinst.com/publications. North America and Europe are leading, but Asia is soon going to have its stake as well.
Tips & Tricks
Maximum HF2 input and output voltages and currents
What are the safe voltages and currents at the HF2 input and output BNCs?
Signal Output 1 and Signal Output 2 can safely output 100 mA with a harmonic distortion of less than -50 dB (the harmonic distortion increases with the output voltage and current). One should keep in mind that as the HF2 output impedance is 50 Ohm, the output voltage will be smaller than the set voltage: this is due to the 50 Ohm output resistor behaving as a voltage divider in conjunction with the load. When driving more than 100 mA, the current will be limited by the output stage protection and the output sine wave will appear clipped at the peaks where the drawn current is maximum (for a non-reactive load). The drive of the 4 Auxiliary Outputs is limited to 20 mA.
Signal Input 1 and Signal Input 2 have a protection diode that conducts when the input voltage exceeds +5 V or -5 V. This prevents high voltage signals from reaching and damaging the front amplifiers. The protection diode itself is designed to dissipate 1 W of continuous power without permanent consequences. In other words, the user should be careful not to supply signals larger than 10 V through a 50 Ohm voltage source. Failing to do so may cause permanent damage to the protection diodes, to the input amplifier and also possibly to the front amplifier power supply.The 2 Auxiliary Inputs have protection diodes with a threshold voltage of +12 V and -12 V; the 32 bit DIO has a maximum output current of 50 mA and the input voltage should be between 0 - 5 V.
- the Signal Outputs can supply in excess of 100 mA without risk of damage; large distortion of the output signal is expected for output currents larger than 100 mA
- the Signal Inputs have protection diodes clipping the signal above 5 V; as a damage threshold rule, the input signals should not exceed 10 V
- special care should be taken when connecting external power supplies to the device, since they can provide large currents with their low-ohmic outputs
- IEEE IFCS & EFTF 2011, Joint Conference of the IEEE International Frequency Control Symposium and European Frequency and Time Forum, San Francisco, May 2-5
- ICOLS 2011, International conference on Laser Spectroscopy, Hannover, May 30-June 3
- Transducers 2011, International Conference on Sensors and Actuators, Beijing, June 5-9