This section provides an overview for lock-in amplifiers as well as their applications and principles. Also, please take a look at the list of 13 lock-in amplifier manufacturers and their company rankings. Here are the top-ranked lock-in amplifier companies as of November, 2024: 1.Hinds Instruments, Inc., 2.GMP SA, 3.Optical Finesse LLC.
Table of Contents
A lock-in amplifier is a device that has a circuit capable of extracting a component signal with a specific frequency from an input signal.
A lock-in amplifier removes noise by multiplying a reference signal and an input signal by a mixer on the device, and extracts a signal of the desired specific frequency by a low-pass filter. A device-specific value called the time constant is set, and the larger the time constant, the smaller the fluctuation of the output signal.
Lock-in amplifiers are often used in the field of optics, especially in spectroscopic measurements. They are sometimes used in combination with microscopes. Specific uses of lock-in amplifiers include astrophysical measurements such as astronomical observations, spectroscopic measurements of thin films on the order of nanometers and other experiments in which weak signals are detected.
In measurements where the sample-derived signal is weak, such as thin films less than several hundred nanometers thick, a device that amplifies the signal and eliminates noise, such as a lock-in amplifier, is indispensable. In addition, it is often used in fluorescence microscopes, Raman spectroscopy microscopes, and probe microscopes, such as atomic force microscopes.
The operating principle of lock-in amplifiers is a circuit like signal processing that detects a signal of a desired specific frequency from an input signal by amplifying the input signal with a preamplifier, multiplying it with a reference signal with a mixer, and removing excess noise components with a low-pass filter.
Within the lock-in amplifier, the input signal is multiplied by the reference signal to produce an output expressed as the sum or difference of the frequencies of the input and reference signals. If Vi=Acos(ωit+Φ) for the input signal and Vr=Bcosωrt for the reference signal, the frequency of the output is proportional to {cos[(ωi-ωr)t+Φ]+cos[(ωi+ωr)t+Φ]}.
However, since the Lock-In Amplifier acts as a low-pass filter, the only remaining component is the signal with ωi-ωr close to 0. In other words, by passing the signal through the Lock-In Amplifier, only the input signal whose frequency is close to that of the reference signal is extracted, and random components such as noise can be removed.
A sine wave is often used as the reference signal for the lock-in amplifier. A square wave is sometimes used as a reference signal to simplify the circuit and reduce cost, but in such cases, the noise rejection performance is inferior to that of a sine wave.
A lock-in amplifier has what is called an inherent time constant. The time constant here is a value expressed as the product of the resistance of a resistor attached to the circuit and the capacitance of a capacitor. Since the magnitude of noise in the output of a lock-in amplifier is proportional to the reciprocal of the time constant, the larger the time constant, the smaller the noise in the output signal. The magnitude of a typical time constant is about 10 milliseconds to 10 seconds, while the time constant of a device that performs digital processing is about 1000 seconds.
A lock-in amplifier is affected by the signal-to-noise ratio (signal-to-noise ratio in dB), which is a measure of the noise level of the input signal. If an amplifier with a poor noise level is used in the preceding stage, the measurement accuracy of the lock-in amplifier will deteriorate, so attention should be paid to the noise level of the input signal.
A chopper is a device that rotates blades in a fixed cycle. High-sensitivity measurement combining a lock-in amplifier and a chopper is one of the most common methods in spectroscopic measurement.
By placing it on the optical path of continuous light, light is blocked when the blade is on the optical path and light is allowed to pass through when the blade is not on the optical path, thereby converting the measured light into a signal with a constant period. In measurements of crystals with large absorption coefficients or optical waveguides with large propagation loss, the measurement light is strongly absorbed by the sample, resulting in a smaller intensity of detectable light and relatively large noise effects.
In such measurements, it is more effective to use a lock-in amplifier and a chopper together. By modulating a signal with low noise and high frequency using a chopper or modulator and demodulating it efficiently using a lock-in amplifier, a signal with low noise can be obtained at the original frequency.
Today's lock-in amplifiers are rapidly becoming digital as their frequencies are extended. A reference signal with an excellent signal-to-noise ratio and a steep low-pass filter are essential to improve the performance of a lock-in amplifier.
By utilizing a PLL (phase-locked loop) to generate a new digital sine wave internally that matches the frequency and phase of an external reference signal, distortion and extraneous noise are suppressed, and a reference signal with excellent signal-to-noise ratio is available. Steep filter characteristics can also be achieved by using a multi-stage digital low-pass filter. With the advent of this digital lock-in amplifier, high-frequency measurements up to 600 MHz can now be realized.
*Including some distributors, etc.
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Femto Messtechnik GmbH, started in 1995 and based in Berlin, Germany, is a manufacturer of amplifier and photoreceiver solutions for scientific and industrial applications. The company sells low-noise preamplifiers, lock-in amplifiers, and photoreceivers, and it serves research labs, scientific institutes, and the electronics industry. It also sells accessories like power supplies, low-noise cables, and connectors, and its products are used in applications such as surface analysis, process control, and ultra-sensitive measurements. The company works with distributors in several countries, including Australia, the USA, and China.
Zurich Instruments AG, founded in Zurich, Switzerland, in 2008 is a manufacturer of test and measurement equipment. The company's product portfolio includes quantum computing control systems, lock-in amplifiers, arbitrary waveform generators, impedance analyzers, and phase-locked loops. Their products are used in markets such as Automotive and Transportation, Telecommunications, Industrial Automation, Healthcare and Medical Devices and Aerospace and Defense. The company also offers customer services that include support, custom research projects and customized services.
NF Corporation was founded in 1959 and is headquartered in Yokohama, Japan. The company serves automobile, clean energy technologies, aerospace, and digital appliance industries. The ISO 9001 and ISO 14001 certified company combines a vertically integrated approach of development, engineering, manufacturing, sales, and field services. The company’s product segments include function modules, electric measurement instruments, and power supply and control products. The company also builds customized products for customers including EMC testing systems, lithium-ion battery charging and discharge testing systems, and bipolar power amplifiers.
GMP SA, founded in 1977 in Renens, Switzerland, is a manufacturer of lasers, photonics, micropositioning, and spectroscopy products. The company's comprehensive product range includes lasers, optical components, micropositioning stages, and spectroscopy equipment. It holds ISO 9001 certification, and the products benefit a wide range of industries, including scientific research, healthcare, telecommunications, and manufacturing, enabling applications such as material analysis, medical diagnostics, and optical communications. It delivers products that meet the specific demands of professionals and businesses in various sectors, ultimately resulting in advancements in technology, research, and industry.
AMETEK Scientific Instruments is based in Oak Ridge, Tennessee, USA, and is an ISO 9001-certified manufacturer of precision analysis instrumentation established in 2006 as a division of AMETEK, Inc. The company produces professional electrochemical, corrosion, and material analysis instruments. These include photoelectrochemical test systems used in solar cell research, frequency response analyzers, and energy storage testing products. The company’s products are mainly used by clients in the research, power generation, and petrochemical sectors.
Stanford Research Systems, located in Sunnyvale, California, has been a designer and manufacturer of test equipment for engineers and scientists since the early 1980s. Its products find applications in various research fields. Its lock-in amplifiers are utilized for recovering nanovolt signals from noisy backgrounds. Additionally, its mass spectrometers can measure residual vacuums down to 10-14 Torr. Its RF signal generators, digital delay generators, and clock synthesizers provide accurate and stable frequency and timing signals. Operating from a 75,000-square-foot facility, the company has collaborated with NASA to adapt its RGA100 quadrupole mass spectrometer for operation in space vacuum conditions.
Hinds Instruments, Inc. is a manufacturer of polarization-based measurement instruments, founded in 1971 and based in Portland, Oregon, United States. The company initiated the commercialization of photoelastic modulators (PEMs) and has since expanded its product line to include various PEM products. These include point and scanning birefringence measurement systems and polarization imaging systems under the Exicor brand. It also offers Mueller polarimeters, PolSNAP waveplate-based Stokes polarimeters and related accessories. The company further manufactures the EKKO series of CD MicroPlate Readers for direct circular dichroism measurement from standard wellplates.
Telco Sensors, established in 1975 and headquartered in Brovst, Jammerbugt, is a designer, developer, and manufacturer of industrial automation and sensing products. Some of its products include photoelectric sensors, photoelectric amplifiers, light curtains, and optical fork sensors. These products find application in various industrial processes and machinery for object detection, safety, and automation. The company is ISO 9001:2015 certified, and all of its products carry a 3-year warranty. The company's network spans six continents and provides around-the-clock service.
UNITRONICS, a company founded in 1989 and headquartered in Ben Gurion Airport, Israel, is a manufacturer and supplier of control and automation solutions. The company’s product portfolio includes the UniStream series of programmable controllers, AC servo drives, and Unitronics VFDs. These products are used in various industries, including the food and beverage industry, oil and gas, and power generation and distribution. The company provides services including technical support, product catalogs, and customization, with additional headquarters in the United States and Germany.
Lambda Photometrics Ltd., incorporated in 1977 and based in Harpenden, England, United Kingdom, is an ISO 9001:2015-certified distributor and service provider specializing in electro-optical instrumentation. The company primarily produces lasers for medical and industrial applications, and electro-optical instrumentation for measurement and analysis. It also offers development and maintenance services for its portfolio lasers, and custom laser-based equipment for unique client projects. The company’s products are mainly used by clients in the industrial manufacturing and automation sectors.
Ranking as of November 2024
Derivation MethodRank | Company | Click Share |
---|---|---|
1 | Hinds Instruments, Inc. |
14.4%
|
2 | GMP SA |
10.8%
|
3 | NF Corporation |
9.5%
|
4 | Optical Finesse LLC |
9.0%
|
5 | FEMTO |
8.6%
|
6 | AMETEK Scientific Instruments |
7.7%
|
7 | Stanford Research Systems |
7.7%
|
8 | Lambda Photometrics Ltd. |
7.2%
|
9 | DEXING MAGNET TECH. CO. |
6.8%
|
10 | Telco |
6.3%
|
Derivation Method
The ranking is calculated based on the click share within the lock-in amplifier page as of November 2024. Click share is defined as the total number of clicks for all companies during the period divided by the number of clicks for each company.Number of Employees
Newly Established Company
Company with a History
*Including some distributors, etc.
Country | Number of Companies | Share (%) |
---|---|---|
Germany | 1 | 25.0% |
Switzerland | 1 | 25.0% |
Japan | 1 | 25.0% |
United Kingdom | 1 | 25.0% |
11 products are listed.
Cons Technology Co., Ltd.
110+ people viewing
■ SR810 (1st place phase) ・ SR830 (2nd phase) A cost -effective digital lock -in amplifier equipped with DSP (Digital Signal Prosessor). ■ Princi...
Cons Technology Co., Ltd.
40+ people viewing
■ Low noise analog lock -in amplifier SR2124 (1st phase, 2nd phase) It is a model that thoroughly pursues the essence of the analog circuit and red...
Cons Technology Co., Ltd.
30+ people viewing
■ 500kHz lock -in amplifier 4MHz lock -in amplifier equipped with a touch screen display. The noise performance is good and can be operated to up t...
Cons Technology Co., Ltd.
40+ people viewing
■ SR850 (2nd phase) DSP digital lock -in amplifier that allows you to check data with a display with a display. The functionality that can measure,...
Cons Technology Co., Ltd.
20+ people viewing
This is a communication bridge for connecting four analog lock-in amplifiers SR124 or voltage control electric current CS580 and computer remote in...
Cons Technology Co., Ltd.
20+ people viewing
■ SR844 (2nd place phase) DSP lock -in amplifier that can be measured from 25kHz to 200MHz. It is possible to measure a small signal in the high -f...
Cons Technology Co., Ltd.
90+ people viewing
■ 100kHz analog lock -in amplifier SR510 (1st place phase) An analog type lock -in amplifier that became the basis of SRS rock -in amplifier. Intui...