ThorLabs SM1 Threaded Kinematic Mirror Mount

The ThorLabs SM1-Threaded Kinematic Mirror Mount delivers precise angular positioning for Ø1″ (25.4 mm) optical components in laser and alignment-critical systems. This mount uses SM1 internal threading (1.035″-40) to secure optics via retaining rings, enabling stable, repeatable adjustments across multiple mounting orientations. Built for engineers who need sub-degree-level control without compromises on thermal stability or wear resistance.

– Technical Specifications

Optical Compatibility
• Optic diameter: Ø1″ (25.4 mm)
• Maximum optic thickness: 0.14″ (3.5 mm) with retaining rings; up to 0.38″ (9.5 mm) with certain variants
• Vacuum-compatible models: up to 0.28″ (7.1 mm) thickness

Angular Adjustment
• Pitch and yaw range: ±4°
• Fine-adjustment resolution: approximately 7.7 mrad/rev or 0.5° per revolution via 1/4″-80 adjusters

Mounting & Mechanical
• Post mount: #8 (M4) counterbored through holes; compatible with Ø1/2″ posts
• Mounting orientations: left-handed, right-handed, or upward-facing
• Retaining mechanism: SM1RR threaded retaining rings (two included)

Materials
• Standard: Black anodized aluminum
• High-stability variants (Polaris®): Heat-treated stainless steel with low coefficient of thermal expansion
• Kinematic contacts: Hardened stainless steel inserts
• Adjustment mechanism: Phosphor bronze bushings and stainless steel lead screws
• Premium models: Hardened stainless steel ball contacts with sapphire seats

– Key Features

• Kinematic three-point design minimizes hysteresis and backlash
• Dual-retaining-ring optic retention for secure hold across orientations
• Compatible with full SM1-threaded component ecosystem (lens tubes, irises, adapters)
• PolarisKA variants engineered for OEM integration with M4 counterbores

– Typical Applications

• Laser cavity alignment and tuning
• Precision optical bench setups
• Research-grade spectroscopy and interferometry
• Vacuum and cryogenic environments (Polaris® models)

– Compatibility & Integration

Direct compatibility with SM1-threaded optical accessories. Vacuum-rated Polaris® models support operation down to 1 × 10⁻⁹ Torr with proper bake-out. PolarisKA mounts available with UHV-specific treatments upon request.