Liquid Cryst a l N oise Ea t e rs U se r Guide
Liquid Crystal Noise Eater Table of Contents Chapter 1 Warning Symbol Definitions ........................................... 0 Chapter 2 Safety ................................................................................. 1 Chapter 3 Product Overview ............................................................. 2 Chapter 4 Setup.................................................................................. 3 4.1. Mounting and Alignment ............................................... 3 4.2.
Liquid Crystal Noise Eater Chapter 1: Warning Symbol Definitions Chapter 1 Warning Symbol Definitions Below is a list of warning symbols you may encounter in this manual or on your device.
Liquid Crystal Noise Eater Chapter 2: Safety Chapter 2 Safety Do Not Open Housing! The Noise Eater has no user-serviceable parts. Service should only be performed by trained service personnel. All statements regarding safety of operation and technical data in this instruction manual will only apply when the unit is operated correctly.
Liquid Crystal Noise Eater Chapter 3: Product Overview Chapter 3 Product Overview Thorlabs’ Liquid Crystal Noise Eaters are precision instruments for stabilizing and attenuating laser power. The noise eater consists of a variable attenuator (liquid crystal wave plate and polarizer), a calibrated beam splitter, and a servo controller to control the modulator, as depicted in the block diagram below.
Liquid Crystal Noise Eater Chapter 4: Setup Chapter 4 Setup 4.1. Mounting and Alignment The noise eater is designed to work with linearly polarized input light aligned with the direction of the arrow near the input aperture. Linearly polarized light and proper alignment of the direction of polarization are important for achieving the best results from the noise eater. In order to minimize optical losses, the noise eater does not have an input polarizer.
Liquid Crystal Noise Eater Chapter 4: Setup Figure 3 Horizontally and Vertically Mounted NEL02A Noise Eaters. Note the direction of the input polarization indicated by the double arrow. 4.2. Power Supply The noise eater operates with 12 V DC power. We recommend using the AC/DC power supply that is included with the noise eater for best performance. 4.3. Powering ON the Noise Eater When the noise eater is connected to the power supply, it automatically powers on. There is no additional power switch.
Liquid Crystal Noise Eater Chapter 5: Operation Chapter 5 Operation 5.1. Selecting the Power Range The NEL02A(/M), NEL03A(/M) and NEL04A(/M) have two selection switches at the top of the case which are used to select the input power range. When the high/low power switch is set to “L”, the input power range can be set from 1 mW to 30 mW, and when the status switch set to “H”, the input power range can be set from 100 mW to 500 mW.
Liquid Crystal Noise Eater Chapter 5: Operation Figure 5 Noise Eaters Normalized Responsivity 5.2. Max Powers at Various Wavelengths The tables below list the maximum input powers for each noise eater, specified for a variety of input wavelengths and switch settings. Please note that these maximum power levels correspond to the feedback electronics of the noise eater, and in some cases, the actual maximum input power is instead limited by the damage threshold of the noise eater.
Liquid Crystal Noise Eater Chapter 5: Operation NEL01A(/M) Max Input Power at Various Wavelengths Power Level Power Level at 450 nm at 550 nm 2 mW 1.5 mW 6 mW 4.5 mW 20 mW 15 mW 60 mW 45 mW Switch Status 1 mW 3 mW 10 mW 30 mW Power Level at 635 nm 1 mW 3 mW 10 mW 30 mW NEL02A(/M) Power Ranges at Various Wavelengths Switch Status L 1 L 2 L 3 L 4 H 1 H 2 H 3 H 4 Power Level at 450 nm Power Level at 550 nm 2 mW 6 mW 20 mW 60 mW 200 mW 600 mWa 1000 mWa Power Level at 635 nm 1.5 mW 4.
Liquid Crystal Noise Eater 5.3. Chapter 5: Operation Modulate the Output Power There is a SMA interface at the right side of the noise eater, which can be used to modulate the attenuation of the noise eater. The modulation input has a 10 kΩ input impedance. A voltage ranging from 0 to 2.5 V can be input to modulate the output power as needed. Before modulating the output power, first turn the output power level knob clockwise to the end of its travel (minimum output power setting).
Liquid Crystal Noise Eater 5.4. Chapter 5: Operation Setting the Output Power Level The noise eater operates by varying how much of the signal is attenuated in order to reach the target output power and attenuate the noise. Since the noise eater can attenuate the signal but not amplify it, the clean output beam can only have a power as high as the minimum power level of the noisy signal.
Liquid Crystal Noise Eater 3. 4. 5. 6. Chapter 5: Operation characteristics of the noise, the signal might need to be recorded over a few minutes to find the minimum. Set the power selector to the suitable value (see Section 5.1). Turn the adjustment knob clockwise until the power reaches 5% below the minimum power you recorded earlier. If you cannot reach the desired power, set the power level to a lower range. Rotate the knob counter clockwise and return to Step 3 to select a different power range.
Liquid Crystal Noise Eater Chapter 6: Specifications Chapter 6 Specifications Item # Operating Wavelength Range NEL01A(/M) NEL02A(/M) NEL03A(/M) NEL04A(/M) 425 – 650 nm 475 – 650 nm 650 – 1050 nm 1050 – 1620 nm Output Power Stability 0.05% (Standard Deviation) a Noise Attenuation Frequency Rangeb DC - 1.8 kHz Noise Attenuation Amplitude Range DC - 1.4 kHz 0.1% to 50% of Input Signal Noise Attenuation Factorc Transmission DC - 2.5 kHz >150 at 10 Hz, 80 at 60 Hz, 10 at 400 Hz, 1.
Liquid Crystal Noise Eater b. c. d. e. f. g. h. Page 12 Chapter 6: Specifications The maximum of the frequency range is defined as the point where 0 dB noise attenuation is obtained. These noise eaters are designed to operate down to DC frequency. However, due to external factors (e.g. ambient temperature, vibration, spatial and/or polarization stability of the light source), the noise attenuation factor below 10 Hz is difficult to measure and quantify.
Liquid Crystal Noise Eater Chapter 7: CE/FCC Certification Chapter 7 CE/FCC Certification In accordance with European Council Directive 2014/30/EU, this product has been assessed against and found compliant with the following Applicable Standards: EN 55011:2009/A1:2010(Class A) EN 61326-1:2013 EN 61326-2-1:2013 EN 61326-2-2:2013 EN 61000-3-2: 2014 EN 61000-4-2:2009 EN 61000-3-3 : 2013 EN 61000-4-3:2006+A1:2008+A2:2010 EN 61000-4-4:2012 EN 61000-4-5:2006 EN 61000-4-6:2014 EN 61000-4-8:2010 EN 61000
Liquid Crystal Noise Eater Page 14 Chapter 7: CE/FCC Certification CTN017430-D02
Liquid Crystal Noise Eater Chapter 8: Maintenance Chapter 8 Maintenance The noise eater does not require maintenance under normal operating conditions. There are no serviceable parts in the noise eater and no reason to open the unit. If you suspect a problem with your noise eater, please call Thorlabs and a member of our Technical Support team will be happy to assist you. 8.1.
Liquid Crystal Noise Eater Chapter 9: Regulatory Chapter 9 Regulatory As required by the WEEE (Waste Electrical and Electronic Equipment Directive) of the European Community and the corresponding national laws, Thorlabs offers all end users in the EC the possibility to return “end of life” units without incurring disposal charges.
Liquid Crystal Noise Eater Chapter 10 Chapter 10: Thorlabs Worldwide Contacts Thorlabs Worldwide Contacts For technical support or sales inquiries, please visit us at www.thorlabs.com/contact for our most up-to-date contact information. USA, Canada, and South America Thorlabs, Inc. sales@thorlabs.com techsupport@thorlabs.com UK and Ireland Thorlabs Ltd. sales.uk@thorlabs.com techsupport.uk@thorlabs.com Europe Thorlabs GmbH europe@thorlabs.com Scandinavia Thorlabs Sweden AB scandinavia@thorlabs.
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