Acousto-Optic Deflectors Gooch & Housego

Product overview of "Acousto-Optic Deflectors"

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Wavelength range: 266-1100 nm; Type: IR, Visible, UV, Mid-IR; Scan Angle: 4.9-60 mrad; Active Aperture: 1.0-60 mm; Operating Frequency: 9.4 μm-432 MHz; Optical Material options: Germanium, Sapphire, Fused Silica, Crystalline Quartz, Tellurium Dioxide

Gooch & Housego's acousto-optic deflectors (AODF) enable precise spatial manipulation of optical beams. Whether for 1D or 2D scanning or fixed-angle deflection, these deflectors ensure uniform diffraction efficiency over the entire scan angle, maintaining a consistent power throughput. These properties are essential for applications in material processing and digital imaging. Gooch & Housego supply a comprehensive range of standard AODF and RF drivers for wavelengths spanning 266-1500 nm.

Distinctive Features:

• Products for visible and NIR wavelengths utilizing in-house grown tellurium dioxide crystals
• UV wavelength products based on fused silica and crystal quartz
• Longitudinal mode broadband products employing a phased array of piezoelectric elements
• High-efficiency products featuring off-axis parallel tangents for slow shear deflection

Choosing the correct RF driver is crucial for achieving optimal scanning speed and precision. Scanning or writing applications necessitate a variable frequency source that is both stable and highly linear. For example, 2D UV beam scanning can be executed by stacking two UV deflectors in series. Gooch & Housego's versatile AODF Dual Driver with phase synchronized outputs offers superior RF driver control for 2D scanning.

Applications: Digital Imaging; Heterodyne Interferometry; Laser Cooling; Laser Marking; Laser Tweezers; Material Processing; Micromachining; Microscopy; On-Line Process Control; Optical Inspection; Photolithography; Printing

Series Wavelength Type Scan Angle Active Aperture Operating Frequency Optical Material Downloads AODF 4070 N/A Mid-IR 60 mrad 9 mm 9.4 μm Germanium Datasheet Driver Driver AODF 2690-UV 266 - 355 nm N/A up to 4.9 mrad up to 7 mm 100 - 432 MHz Sapphire Datasheet Driver Driver AODF 4200-UV 266 nm UV 5.5 mrad 1.0 x 60.0 mm 135 - 265 MHz Fused Silica Datasheet Driver Driver AODF 4170 355 nm UV 4.9 mrad 7 mm 130 - 210 MHz Crystalline Quartz Datasheet Driver Driver AODF 4100-UV 364 nm UV 29.5 mrad 4.0 x 14.0 mm 75 - 125 MHz Tellurium Dioxide Datasheet Driver Driver AODF 4200-VI 405 - 488 nm Visible 58 mrad 4.8 mm 150 - 250 MHz Tellurium Dioxide Datasheet Driver Driver AODF 4090-7 440 - 530 nm Visible 44 mrad 8.5 mm 60 - 115 MHz Tellurium Dioxide Datasheet Driver Driver AODF 4100-VI 488 nm Visible 39.5 mrad 4.0 - 14 mm 75 - 125 MHz Tellurium Dioxide Datasheet Driver Driver AODF 4055-4 780 - 980 nm IR 44.3 mrad 3.5 x 14 mm 35 - 70 MHz Tellurium Dioxide Datasheet Driver Driver AODF 4210-IR 830 nm IR 27.6 mrad 2.0 - 6.0 mm 140 - 280 MHz Tellurium Dioxide Datasheet Driver Driver AODF 4090-6 1064 nm IR 56 mrad 2 mm 72.5 - 107.5 MHz Tellurium Dioxide Datasheet Driver AODF 4075-IR 1065 - 1100 nm IR 8.1 mrad 2.5 mm 59 - 91 MHz Tellurium Dioxide Datasheet Driver Driver

We provide a comprehensive range of acousto-optic Q-switches, including water- and air-cooled options, operating at RF frequencies of 27MHz, 41MHz, and 80MHz, suited for industrial standards.

The acousto-optical Q-switch functions by harnessing the interaction between an ultrasonic wave and a light beam within a scattering medium. When the light beam enters at a Bragg angle relative to the acoustic wave's surface in the medium, it is diffracted according to periodic changes in the diffraction rate caused by the acoustic wave.

Briefly explained, an RF signal is applied to the transducer attached to molten quartz, initiating thickness extensional vibration. This generates ultrasonic shear waves within the quartz, forming a phase grating due to acoustic waves. When the laser beam aligns with this phase grating at the Bragg angle, it gets diffracted and spatially separated from the incoming light. In a laser optical resonator against 0-dimensional diffracted light (undiffracted), the diffracted light shifts from the resonator axis upon RF signal application, leading to losses and suppression of laser oscillation. This phenomenon is harnessed by applying an RF signal temporarily to achieve low Q-value and halt laser oscillation. During this time, the Nd:YAG rod's population inversion accumulates through continuous pumping. Once the RF signal ceases (high Q-value), removing the loss, the stored energy releases as a laser pulse in a short duration, forming Q-switch pulses.

This process is briefly overviewed. By subjecting the RF signal to pulse modulation, periodic extraction of Q-switch pulses becomes feasible. However, if Q-switch pulses' period falls below the higher-order Nd:YAG rod’s lifespan (about 200 ms), population inversion reduces, thereby lowering the peak value of Q-switch pulses.

For further insights into the principle, please click here.

Standard QS24/27 Series Industrial Q-switches

A water-cooled acousto-optic Q-Switch designed for use in high-power Nd:YAG laser systems. By integrating top-grade fused silica, high-quality optical finishing, and in-house anti-reflection coatings, this Q-Switch offers minimal insertion loss and a high damage threshold. Its innovative design and manufacturing process enable the application of RF powers up to 100W.

Standard options encompass various frequencies (24 to 68MHz), active apertures (1 to 8mm), acoustic modes (compressional for linear polarization, shear for unpolarized), and water connectors. Customized housings are available for OEMs.

Specifications

• Model no: Refer to "Options" below

• Interaction medium: Fused silica

• Operational wavelength: 1064nm

• Anti-reflection coating: Hard multi-layer dielectric

• - Reflectivity: <0.2% per surface (<0.1% typical)

• - Damage threshold: ＞ 500MW cm-2

• Insertion loss: <10% (<5% typical)

• Active aperture: Refer to "Options" below

• Diffraction (separation) angle: ~4.8 mrad

• VSWR: 1.2:1

• Maximum CW drive power: 100W

• Thermal interlock: +50°C

• Water Cooling

• Flow rate: 190cc/min (minimum)

• Water Temperature:

• - Recommended operating: 32°C

• - Recommended maximum: 40°C

• Water Connectors: Refer to "Options" below

Stallion Series Acousto-Optic Q-Switches

A 'Stallion' version of our industry-standard water-cooled Acousto-optic Q-Switch for high-power lamp or diode pumped Nd:YAG lasers.

The patent-pending 'Stallion' manufacturing technique offers superior corrosion resistance while retaining optimal performance and RF power handling up to 100W.

This Q-Switch combines high-quality fused silica with top-grade optical finishing and in-house anti-reflection coatings, resulting in very low insertion loss and a high damage threshold.

Besides the standard product shown, custom configurations are available for specialized applications. These include alternative housing options, wavelengths, and RF frequencies.

Key Features:

• Industry standard for Nd:YAG lasers

• Superior corrosion resistance

• Stainless steel cooling channels

• High damage threshold

• Push-fit water connectors

• Up to 100W RF power handling

• Custom configurations available

Applications:

• Material processing:

• Laser marking

• Laser engraving

• Laser cutting

• Laser drilling

• Medical (surgery)

• Lithography

General Specifications:

Interaction material: Fused Silica; Wavelength: 1064nm; AR coating reflectivity: Damage threshold: <0.2% per surface ＞ 1GW cm-2; Transmission (single pass): ＞ 99.6%; Static insertion loss: ≤ 6% at 50W laser power; VSWR: <1.2:1 (<1.4:1 at 50W RF power); RF power rating: 100W CW (max); Water flow rate: ＞ 190cc/minute; Water-cooling channel material: Recommended water temperature:
Thermal switch cut-off: Stainless steel 316; +22°C to +32°C; +55°C +/- 5°C

Are you interested in learning more about acousto-optic q-switch driver? Contact us today to secure an expert consultation!

Ordering Codes: Example: I-QS027-4S4G-N5-ST1 (Q-Switch, 27.12MHz, 4mm active aperture, shear mode, fused silica, 1064nm, 4mm OD straight push-fit water connectors, BNC, Stallion housing with M3 mounting holes)

How to Find the Replacement of the Used/damaged Q-switch

1. Identify the frequency of the RF driver (Q-switch driver).

2. Determine the diameter of the YAG rod or the laser beam diameter from the laser head. Generally, the Q-switch aperture is 1mm larger than the YAG rod diameter.

3. If the laser resonator lacks a polarizer and the laser beam is non-polarized, acoustic mode S should be used. Otherwise, acoustic mode C is used for polarized laser beams. (Note: This is not 100% accurate. Acoustic mode S is used effectively in polarized lasers and vice versa.)

4. Choose a suitable water connector. Note that you can replace the water connector if necessary since the connector is screwed. For instance, if the damaged Q-switch has a B-connector and the new one has an S-connector, you can swap the B-connector from the old Q-switch to the new one.

RF Power for Q-switches:

The following table shows the RF power requirements for Q-switches at theoretical peak loss modulations:

Aperture size Compressional peak RF power Shear peak RF power 2mm ~20W ~60W 3mm ~25W ~90W 4mm ~35W ~100W 5mm ~50W ~100W

• Note: The maximum allowed RF input is 100W.

Comparison between Standard Series Q-switches and Stallion Q-switches

Stallion, I-QS27 series Standard QS27-xx-x series Water-cooling pad remains aluminum to avoid corrosion (prevent oxidation) Water-cooling pad is aluminum, lacks coating (prone to corrosion) Inner water duct: 3.5mm diameter coated with stainless steel Inner water duct: 2.5mm diameter Same dimension and screw hole position as QS27 series; International standard screws (M3) Old UK standard screws Water connector options: right-angle and straight through Only straight through version; Water connector diameters: 4mm or 6mm; Laser marking for serial number (unerasable); Sticker for part number and serial number (easily erasable)

New part number of Stallion versus the older model :

Stallion Q-switch series Old Q-switch series I-QS27-5S4G-U5-ST1 QS27-5S-x I-QS27-3S4G-U5-ST1 QS27-3S-x I-QS27-5C4G-U5-ST1 QS27-5C-x I-QS27-4S4G-U5-ST1 QS27-4S-x

Comparing Stallion and old Q-switches. The primary visual difference lies in the water connector.

AO Q-Switch Models for 1064nm (Water cooled)

Model No. I-QS027-4C10G-x5-ST7 Device AO Q-Switch Interaction material Crystal Quartz Wavelength 1064nm AR coating reflectivity: <0.2% per surface Damage threshold: ＞ 1GW/cm2 Transmission: ＞99.6% Frequency: 27.12MHz Polarization: Linear, vertical to base Active Aperture: 4.0mm Acoustic Mode: Compressional Loss Modulation: ＞80% Max RF Power: 75W Water flow rate: ＞0.2l/min Recommended water temperature: 22°C to 32°C Thermal switch cut-off: 65°C ± 5% Housing: Stallion, St/St 316 water channels Water connectors: To be specified

AO Q-Switch at Other Wavelengths (Water Cooled)

Model No. QS027-4J-xxx I-QS027-5S4Y-x5-ST1 Interaction material Fused Silica (Infrasil, water-free) Fused Silica (Infrasil, water-free) Wavelength 1550nm 946nm AR coating reflectivity: <0.2% per surface at 1550nm <0.2% per surface at 1550nm Damage threshold: ＞ 500MW/cm2 ＞ 1GW/cm2 Polarization: Random Random Interaction length: 46.0mm 46.0mm RF frequency: 27.12MHz 27.12MHz VSWR: <1.2:1 <1.