Zygo 7702

2. Product Introduction

• ZYGO 7702 belongs to ZYGO’s proprietary ZMI™ series displacement measuring interferometer core laser source, factory-developed continuous-wave helium-neon heterodyne polarized laser module exclusively designed for ultra-precision industrial metrology and closed-loop motion position feedback measurement systems.
• This product outputs two orthogonally polarized laser beams with fixed frequency offset, matches full-series ZYGO signal acquisition boards including 4104C, serves as core light source for laser interferometry measurement equipment, and is applicable for lab calibration and continuous 24/7 industrial production onsite deployment.
• Product complies with US NCDRH Class II laser safety certification and global CE electrical safety specification, standardized industrial-grade laser measurement component for nanoscale precision dimensional inspection.

3. Model Series Classification

• Base core series: ZYGO ZMI™ series, affiliated product models include ZMI7701, ZMI7712, ZMI7714, ZMI7722, ZMI7724 as extended derivative laser heads.
• Internal sub-model classification of ZYGO7702 (defined by suffix code 31/32/33/34/35/36):
  1. Submodel 31: Output power＞400µW, beam diameter=6mm, Narrow mounting base structure
  2. Submodel 32: Beam diameter=3mm, undefined rated output power, non-standard mounting base
  3. Submodel 33: Output power＞400µW, beam diameter=6mm, non-standard mounting base
  4. Submodel 34: Beam diameter=3mm, Wide mounting base structure, undefined rated output power
  5. Submodel 35: Beam diameter=6mm, non-standard mounting base, undefined rated output power
  6. Submodel 36: Output power＞525µW, beam diameter=3mm, Narrow mounting base structure

4. Material Composition

• Outer enclosure casting material: High-density industrial aluminum alloy, integral die-cast molding for whole outer shell
• Mounting foot raw material: Ultem 2400 high-performance PEI engineering plastic for all Narrow-type installation bases
• Internal laser tube shell: Sealed borosilicate vacuum glass tube filled with helium-neon mixed inert gas
• Internal optical element substrate: Ultra-low-expansion fused silica glass for AOM, turning mirrors and spatial filter components
• Internal circuit baseboard: FR-4 flame retardant glass fiber printed circuit board; heating coil: bifilar wound alloy resistance wire for laser tube constant-temperature heating
• External connecting cable jacket: Oil-resistant polyurethane insulation material, nominal reserved cable clearance dimension: 135mm

5. Structural Feature Description

• Overall outer dimension: 458.9mm(L) ×124.0mm(W) ×72.0mm(H), net overall equipment weight: 5.5kg for all standard sub-models
• Split two-type bottom mounting structure: Narrow base mounting structure and Wide base mounting structure corresponding to different suffix sub-models
• Internal layered layout: Front-end beam output chamber → Acousto-Optic Modulator(AOM) assembly → dual turning mirror group → spatial filter component → built-in HeNe laser tube with constant-temperature heating unit → rear-end switching power supply module, all components fixed by aluminum positioning bracket inside sealed casing
• Single-side rear panel layout: Built-in DC power input aviation socket, laser warning identification label, CE certification marking, beam outlet reserved on front end face of equipment shell
• Integral closed shell design with dustproof sealing rubber strips between upper cover and bottom casting to avoid internal optical path contamination from ambient dust

6. Core Technical Specifications & Performance Parameters

6.1 Laser Optical Core Parameters

• Laser medium type: Helium-Neon(HeNe), Continuous Wave(CW), Heterodyne dual-frequency linearly polarized laser
• Vacuum wavelength of two polarized beams:
  • F1 (Vertical polarization): 632.991501nm
  • F2 (Horizontal polarization): 632.991528nm
• Fixed frequency difference between dual-frequency output: 20MHz ±1600Hz
• Wavelength short-term stability: 0.005ppm per hour; long-term 24h stability: 0.01ppm/24h; full service lifetime wavelength accuracy: ±0.1ppm
• Output optical power grading: Standard low-power＞400µW; high-power grade＞525µW; maximum peak output optical power ≤1mW
• Optional outgoing beam diameter specifications: 3mm / 6mm determined by sub-model coding
• Beam pointing thermal stability: ＜0.5arcsec/℃ under full operating temperature range

6.2 Electrical Power Parameters

• Rated DC input power supply: +15VDC±0.5V @2.1A; -15VDC±0.5V @1.2A
• Max power consumption during warm-up startup stage: 50W; stable continuous operation max power dissipation: 39W

6.3 Startup Timing Parameters

• Time from power-on to effective laser beam emission: Typical＜10s, absolute maximum startup duration ≤70s
• Time required to reach full wavelength stability after startup: Typical 10min continuous preheating

6.4 Environmental Adaptability Parameters

• Rated continuous operating ambient temperature range: 10℃ ~30℃, non-condensing relative humidity: 0%~90%RH
• Non-operational storage temperature range: -40℃~75℃, non-condensing relative humidity:0%~90%RH
• Anti-shock specification under non-operating state: 40g peak acceleration within 11ms pulse duration applied on three orthogonal mechanical axes

6.5 Measurement Performance Derived Parameters

• Matching interferometer measurement resolution: Sub-nanometer grade, minimum measurable displacement resolution ≤0.1nm
• System cyclic measurement error: ≤1nm across full effective measurement stroke
• Maximum expandable measurement axes quantity driven by single laser head: Up to 16 independent measurement axes via external beam splitter optical components

6.6 Laser Safety Grade

• US DHHS laser classification: Class II laser product, fully compliant with NCDRH federal laser safety regulatory standards

7. Functional Characteristics

1. Dual orthogonal polarized beam output with fixed 20MHz frequency offset, generates stable heterodyne beat signal for Doppler shift displacement calculation via matched photoelectric receiving module
2. Compatible multi-axis split measurement function, single laser source can allocate multiple measurement optical paths by external beam splitters to realize synchronous multi-station position detection
3. Built-in constant-temperature bifilar heating system for internal HeNe laser tube, automatically compensates ambient temperature fluctuation to lock laser wavelength stability throughout long-term operation
4. Native electrical matching with ZYGO proprietary MetroPro® measurement software and 4104 series digital signal acquisition boards, supports real-time data output via USB2.0 and RS232 dual communication interfaces
5. Supports multiple measurement mode switching: linear displacement measurement, angular deflection measurement, straightness error detection and surface flatness inspection via different external interferometer optical accessories
6. Low-power standby energy-saving function, standby power consumption reduces 30% compared with legacy ZMI early-generation laser heads to adapt uninterrupted 24h industrial operation

8. Working Principle

1. Internal sealed HeNe glass tube generates single longitudinal-mode fundamental 632.99nm continuous laser after power supply energization and preheating temperature stabilization controlled by built-in heating coil.
2. Original single-frequency laser beam transmits to internal Acousto-Optic Modulator(AOM) component, AOM splits single laser into two orthogonally polarized light beams with fixed 20MHz frequency deviation to form dual-frequency heterodyne output source.
3. Split dual-frequency beam passes through internal turning mirror group and spatial filter to optimize beam collimation and spot uniformity before outgoing from front equipment outlet.
4. One beam is defined as fixed reference beam reflected by stationary retroreflector inside signal receiving end; another measurement beam projects onto moving measured target and returns after target reflection, two beams converge at photodiode detector to produce fixed beat frequency signal via heterodyne interference effect.
5. Target linear movement causes Doppler frequency shift of returned measurement beam, the phase difference between shifted measured beat signal and original fixed reference signal is converted into precise displacement value by matched ZYGO 4104C acquisition board and MetroPro software calculation to complete high-precision position measurement.

9. Product Advantage Highlights

1. Ultra-high long-term wavelength stability ensures sub-nanometer measurement precision without frequent field recalibration, reduces routine equipment maintenance workload for production line application
2. Compact integrated aluminum cast housing with optimized internal optical path layout, strong anti-vibration and anti-ambient temperature interference capacity for harsh industrial workshop environment
3. Class II low-power laser safety design eliminates complex laser protection shielding requirement during onsite installation and operation, lowering system construction cost
4. Wide compatibility with full-range ZYGO interferometry accessories and third-party precision motion platforms, flexible configuration to customize single/multi-axis measurement scheme per customer requirement
5. Factory-customized two mounting base options (Narrow/Wide) adapt different installation space limitation of precision equipment cabinet and motion stage structure
6. Factory certified HeNe laser tube design with rated service lifespan up to 50000 continuous operating hours, extended service cycle reduces spare part replacement frequency
7. Ultra-low cyclic measurement error ≤1nm outperforms mainstream peer laser heads with 10~20nm inherent cyclic error, guarantees accurate measurement over long-distance travel stroke

10. Applicable Industry & Specific Application Scenarios

10.1 Semiconductor Manufacturing Industry

• Wafer lithography equipment stage closed-loop position feedback, photomask overlay error inspection, semiconductor wafer surface flatness & thickness metrology, chip packaging precision positioning detection

10.2 Aerospace & Defense Precision Engineering

• Aerospace component dimensional tolerance inspection, adaptive optical telescope mirror positioning calibration, precision weapon targeting system position closed-loop control, aircraft critical part flatness detection

10.3 Precision Optical Component Fabrication

• Lens surface curvature & roughness measurement, optical glass thin-film thickness detection, prism and mirror processing contour inspection, optical assembly coaxiality calibration

10.4 Nanotechnology & Scientific Research Laboratory

• Nano-positioning platform step precision calibration, scanning probe microscopy stage displacement monitoring, university metrology lab standard calibration equipment, MEMS micro-component dimensional testing

10.5 High-End Precision Machinery & Automation

• CNC ultra-precision machine tool feed axis position feedback, industrial robotic arm end effector positioning inspection, bearing and high-precision screw pitch error measurement

11. Formal Installation Requirements

1. Mounting base selection rule: Install Narrow-type fixed accessories for submodel 31/36; select Wide-type fixed accessories exclusively for submodel34; remaining submodels match customized installation fixture according to actual equipment cabinet dimension
2. Installation ambient precondition: Ensure installation site ambient temperature stabilized within 10℃~30℃, relative humidity below 90%RH with zero condensation, avoid direct air-conditioner airflow blowing on laser head casing surface
3. Mechanical fixing specification: Use grade 8.8 high-strength stainless steel bolts to lock mounting base onto vibration-isolated marble platform or equipment fixed base; installation base flatness tolerance ≤0.02mm per 100mm length to prevent casing deformation causing internal optical path offset
4. Power wiring requirement: Connect +15V/-15V DC power strictly following terminal polarity marked on rear panel socket, use shielded DC cable to isolate external electromagnetic interference, reserved cable bending clearance maintains fixed 135mm as factory nominal standard
5. Beam path layout requirement: Reserve minimum 200mm free space at front beam outlet without any blocking object to avoid beam occlusion and reflected stray light back into laser internal optical components
6. Installation surrounding restriction: Keep installation position away from strong electromagnetic equipment (frequency converter, high-power motor) within 1.5m distance to eliminate electromagnetic disturbance affecting frequency stability

12. In-Use Precautions

1. Startup preheating regulation: After power-on, reserve minimum 10min continuous warm-up time before formal measurement operation to reach full wavelength stability status, prohibit data collection during incomplete preheating period
2. Operating environment prohibition: Strictly forbid continuous operation under ambient temperature beyond 10℃~30℃ or condensation humidity condition; long-term out-of-range environment will cause irreversible drift of laser wavelength and internal optical component damage
3. Mechanical handling restriction: Equipment net weight is 5.5kg; forbid single-point lifting and violent collision during shifting, avoid falling impact which triggers internal laser tube fracture and optical path misalignment
4. Daily maintenance rule: Regularly clean front beam outlet lens surface with dust-free nitrogen blowing; never wipe optical surface with ordinary rag or organic solvent to prevent coating corrosion damage
5. Storage precaution: For long-term idle storage, place equipment within -40℃~75℃ dry non-condensing environment, disconnect external DC power supply to avoid continuous standby aging of internal heating components
6. Safety operation specification: Although Class II laser eye protection relies on human blink reflex, prohibit intentional long-time direct staring at outgoing laser beam to eliminate potential cumulative eye injury risk
7. Fault maintenance restriction: Disassemble outer aluminum casing only by ZYGO certified professional maintenance personnel; unauthorized opening destroys internal optical path calibration and voids original factory product warranty