BK 7 Precision Bi-Concave Lenses

BK 7 optical glass
≤λ/4 surface irregularity, 40-20 scratch-dig
Broadband or laser line AR coatings available
Standard diameters and focal lengths

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Designed to meet the demanding requirements of laser electro-optic applications, Newport's BK 7 precision bi-concave lenses are manufactured from fine annealed optical glass and are polished to tight tolerances using master test plates to ensure minimum wavefront distortion. Tight surface quality tolerances minimize scatter and unwanted diffraction effects.

BK 7 is an excellent material for most visible and near infrared applications. It is the most common optical glass, and it provides great performance at a good value.

Standard diameters from 6.35 mm to 50.8 mm allow for quick, easy mounting in many Newport holders when building experiments or prototypes and complete upgradeable from BK 7 to fused silica singlets.

Standard focal lengths provide a systematic approach allowing lenses of different sizes to be interchanged. These singlet lenses are available either uncoated or multi-layer antireflection coated with a choice of broadband coatings or a laser line V-coating for 1064 nm.

Specifications

Focal Length at 589 nm	±1 %
Material	BK 7, grade A, fine annealed optical glass or equivalent
Wavelength	380–2100 nm, uncoated
Surface Accuracy	1.5 λ (1.5 λ) power, (λ/4) irregularity at 546.1 nm over the clear aperture
Clear Aperture	≥central 90% of diameter
Surface Quality	40-20 scratch-dig
Centration, Spherical Lenses	≤3 arc min
Diameter Tolerance	+0/-0.1 mm
Center Thickness (T_c)	2.5 ±0.1 mm
Edge Thickness (T_e) Tolerance	Nominal Value (see below)
Chamfers	0–0.8 mm face width x 45° ±15°, typical
Antireflection Coating	AR.14 , AR.16 , and AR.18 : broadband, multilayer antireflection coating, R_avg <0.5% AR.33 : laser line, multilayer V-coat, R_max <0.25%
Durability	MIL-C-675C, moderate abrasion
Cleaning	Non-abrasive method, acetone or isopropyl alcohol on lens tissue recommended (see Care and Cleaning of Optics)
Damage Threshold	AR.14 -AR.18 : 1000 W/cm², 2 J/cm² with 10 nsec pulses @ 1064 nm, typical AR.33 : 2000 W/cm², 3 J/cm² with 10 nsec pulses @ 1064 nm, typical

Substrate Specifications Table

Model	Diameter (mm)	Focal Length (mm)	f/#	BFL , FFL (mm)	P₁ (mm)	P₂ (mm)	T_e (mm)	R (mm)
Model	Diameter (mm)	Focal Length (mm)	f/#	BFL , FFL (mm)	P₁ (mm)	P₂ (mm)	T_e (mm)	R (mm)
KBC013	6.35	-6.3	-0.9	-7.02	0.77	-0.77	3.75	-6.861
KBC010	6.35	-12.5	-1.9	-13.29	0.79	-0.79	3.12	-13.333
KBC028	12.7	-12.5	-0.9	-13.29	0.79	-0.79	5.07	-13.333
KBC025	12.7	-25	-1.9	-25.81	0.81	-0.81	3.76	-26.259
KBC022	12.7	-50	-3.9	-50.81	0.81	-0.81	3.13	-52.103
KBC019	12.7	-75	-5.9	-75.82	0.82	-0.82	2.92	-77.943
KBC016	12.7	-100	-7.8	-100.82	0.82	-0.82	2.82	-103.785
KBC046	25.4	-25	-0.9	-25.81	0.81	-0.81	7.74	-26.259
KBC043	25.4	-50	-1.9	-50.81	0.81	-0.81	5.04	-52.103
KBC040	25.4	-75	-2.9	-75.82	0.82	-0.82	4.19	-77.943
KBC037	25.4	-100	-3.9	-100.82	0.82	-0.82	3.76	-103.785
KBC034	25.4	-150	-5.9	-150.82	0.82	-0.82	3.34	-155.466
KBC031	25.4	-200	-7.8	-200.82	0.82	-0.82	3.13	-207.148
KBC085	50.8	-75	-1.4	-75.82	0.82	-0.82	9.36	-77.943
KBC082	50.8	-100	-1.9	-100.82	0.82	-0.82	7.60	-103.785
KBC079	50.8	-150	-2.9	-150.82	0.82	-0.82	5.88	-155.466
KBC076	50.8	-200	-3.9	-200.82	0.82	-0.82	5.03	-207.148
KBC073	50.8	-250	-4.9	-250.82	0.82	-0.82	4.52	-258.824
KBC070	50.8	-500	-9.8	-500.82	0.82	-0.82	3.51	-517.255

Antireflection Coatings

Wavelength Range (nm)	Center Wavelength (nm)	Reflectivity per Surface	Angle of Incidence	Coating Type
430–700	530	R_avg <0.5%	0–15°	AR.14
650–1000	790	R_avg <0.5%, R_max <1.5	0–15°	AR.16
1000–1550	1210	R_avg <0.5%, R_max <1.5%	0–15°	AR.18
1064	1064	R_max <0.25%	0–15°	AR.33

Antireflection coating specifications can be found on Broadband Multilayer Antireflection Coatings and Laser Line Antireflection V-Coatings.

Model	Description	avail raw	Availability	price raw	Price	Qty. MULTI ADD
KBC010	BK 7 Bi-Concave Lens, 6.35 mm Diameter, -12.5 mm EFL, Uncoated	11	11 Weeks	36	$36.00	ADD
KBC010AR.14	BK 7 Bi-Concave Lens, 6.35 mm Diameter, -12.5 mm EFL, 430-700nm	0	In Stock	52	$52.99	ADD
KBC010AR.16	BK 7 Bi-Concave Lens, 6.35 mm Diameter, -12.5 mm EFL, 650-1000nm	0	In Stock	62	$62.00	ADD
KBC010AR.18	BK 7 Bi-Concave Lens, 6.35 mm Diameter, -12.5 mm EFL, 1000-1550nm	0	In Stock	62	$62.00	ADD
KBC010AR.33	BK 7 Bi-Concave Lens, 6.35 mm Diameter, -12.5 mm EFL, 1064nm	0	In Stock	83	$83.00	ADD
KBC013	BK 7 Bi-Concave Lens, 6.35 mm Diameter, -6.3 mm EFL, Uncoated	0	In Stock	35	$35.00	ADD
KBC013AR.14	BK 7 Bi-Concave Lens, 6.35 mm Diameter, -6.3 mm EFL, 430-700nm	0	In Stock	50	$50.00	ADD
KBC013AR.16	BK 7 Bi-Concave Lens, 6.35 mm Diameter, -6.3 mm EFL, 650-1000nm	0	In Stock	62	$62.00	ADD
KBC013AR.18	BK 7 Bi-Concave Lens, 6.35 mm Diameter, -6.3 mm EFL, 1000-1550nm	11	11 Weeks	62	$62.00	ADD
KBC013AR.33	BK 7 Bi-Concave Lens, 6.35 mm Diameter, -6.3 mm EFL, 1064nm	0	In Stock	80	$80.00	ADD
KBC016	BK 7 Bi-Concave Lens, 12.7 mm Diameter, -100 mm EFL, Uncoated	0	In Stock	35	$35.00	ADD
KBC016AR.14	BK 7 Bi-Concave Lens, 12.7 mm Diameter, -100 mm EFL, 430-700nm	11	11 Weeks	52	$52.00	ADD
KBC016AR.16	BK 7 Bi-Concave Lens, 12.7 mm Diameter, -100 mm EFL, 650-1000nm	11	11 Weeks	62	$62.00	ADD
KBC016AR.18	BK 7 Bi-Concave Lens, 12.7 mm Diameter, -100 mm EFL, 1000-1550nm	0	In Stock	62	$62.00	ADD
KBC016AR.33	BK 7 Bi-Concave Lens, 12.7 mm Diameter, -100 mm EFL, 1064nm	11	11 Weeks	81	$81.00	ADD
KBC019	BK 7 Bi-Concave Lens, 12.7 mm Diameter, -75 mm EFL, Uncoated	0	In Stock	35	$35.00	ADD
KBC019AR.14	BK 7 Bi-Concave Lens, 12.7 mm Diameter, -75 mm EFL, 430-700nm	0	In Stock	52	$52.00	ADD
KBC019AR.16	BK 7 Bi-Concave Lens, 12.7 mm Diameter, -75 mm EFL, 650-1000nm	0	In Stock	62	$62.00	ADD
KBC019AR.18	BK 7 Bi-Concave Lens, 12.7 mm Diameter, -75 mm EFL, 1000-1550nm	0	In Stock	62	$62.00	ADD
KBC019AR.33	BK 7 Bi-Concave Lens, 12.7 mm Diameter, -75 mm EFL, 1064nm	11	11 Weeks	81	$81.00	ADD
KBC022	BK 7 Bi-Concave Lens, 12.7 mm Diameter, -50 mm EFL, Uncoated	0	In Stock	35	$35.00	ADD
KBC022AR.14	BK 7 Bi-Concave Lens, 12.7 mm Diameter, -50 mm EFL, 430-700nm	0	In Stock	50	$50.00	ADD
KBC022AR.16	BK 7 Bi-Concave Lens, 12.7 mm Diameter, -50 mm EFL, 650-1000nm	0	In Stock	62	$62.00	ADD
KBC022AR.18	BK 7 Bi-Concave Lens, 12.7 mm Diameter, -50 mm EFL, 1000-1550nm	0	In Stock	62	$62.00	ADD
KBC022AR.33	BK 7 Bi-Concave Lens, 12.7 mm Diameter, -50 mm EFL, 1064nm	0	In Stock	80	$80.00	ADD
KBC025	BK 7 Bi-Concave Lens, 12.7 mm Diameter, -25 mm EFL, Uncoated	0	In Stock	35	$35.00	ADD
KBC025AR.14	BK 7 Bi-Concave Lens, 12.7 mm Diameter, -25 mm EFL, 430-700nm	0	In Stock	50	$50.00	ADD
KBC025AR.16	BK 7 Bi-Concave Lens, 12.7 mm Diameter, -25 mm EFL, 650-1000nm	0	In Stock	59	$59.00	ADD
KBC025AR.18	BK 7 Bi-Concave Lens, 12.7 mm Diameter, -25 mm EFL, 1000-1550nm	0	In Stock	62	$62.00	ADD
KBC025AR.33	BK 7 Bi-Concave Lens, 12.7 mm Diameter, -25 mm EFL, 1064nm	0	In Stock	84	$84.00	ADD
KBC028	BK 7 Bi-Concave Lens, 12.7 mm Diameter, -12.5 mm EFL, Uncoated	11	11 Weeks	35	$35.00	ADD
KBC028AR.14	BK 7 Bi-Concave Lens, 12.7 mm Diameter, -12.5 mm EFL, 430-700nm	0	In Stock	52	$52.00 $53.00	ADD
KBC028AR.16	BK 7 Bi-Concave Lens, 12.7 mm Diameter, -12.5 mm EFL, 650-1000nm	0	In Stock	59	$59.00	ADD
KBC028AR.18	BK 7 Bi-Concave Lens, 12.7 mm Diameter, -12.5 mm EFL, 1000-1550nm	0	In Stock	59	$59.00	ADD
KBC028AR.33	BK 7 Bi-Concave Lens, 12.7 mm Diameter, -12.5 mm EFL, 1064nm	0	In Stock	81	$81.00	ADD
KBC031	BK 7 Bi-Concave Lens, 25.4 mm Diameter, -200 mm EFL, Uncoated	0	In Stock	37	$37.00	ADD
KBC031AR.14	BK 7 Bi-Concave Lens, 25.4 mm Diameter, -200 mm EFL, 430-700nm	0	In Stock	52	$52.00	ADD
KBC031AR.16	BK 7 Bi-Concave Lens, 25.4 mm Diameter, -200 mm EFL, 650-1000nm	0	In Stock	62	$62.00	ADD
KBC031AR.18	BK 7 Bi-Concave Lens, 25.4 mm Diameter, -200 mm EFL, 1000-1550nm	11	11 Weeks	62	$62.00	ADD
KBC031AR.33	BK 7 Bi-Concave Lens, 25.4 mm Diameter, -200 mm EFL, 1064nm	11	11 Weeks	84	$84.00	ADD
KBC034	BK 7 Bi-Concave Lens, 25.4 mm Diameter, -150 mm EFL, Uncoated	0	In Stock	35	$35.00	ADD
KBC034AR.14	BK 7 Bi-Concave Lens, 25.4 mm Diameter, -150 mm EFL, 430-700nm	0	In Stock	52	$52.00	ADD
KBC034AR.16	BK 7 Bi-Concave Lens, 25.4 mm Diameter, -150 mm EFL, 650-1000nm	0	In Stock	62	$62.00	ADD
KBC034AR.18	BK 7 Bi-Concave Lens, 25.4 mm Diameter, -150 mm EFL, 1000-1550nm	11	11 Weeks	62	$62.00	ADD
KBC034AR.33	BK 7 Bi-Concave Lens, 25.4 mm Diameter, -150 mm EFL, 1064nm	11	11 Weeks	85	$85.00	ADD
KBC037	BK 7 Bi-Concave Lens, 25.4 mm Diameter, -100 mm EFL, Uncoated	0	In Stock	37	$37.00	ADD
KBC037AR.14	BK 7 Bi-Concave Lens, 25.4 mm Diameter, -100 mm EFL, 430-700nm	0	In Stock	52	$52.00	ADD
KBC037AR.16	BK 7 Bi-Concave Lens, 25.4 mm Diameter, -100 mm EFL, 650-1000nm	0	In Stock	62	$62.00	ADD
KBC037AR.18	BK 7 Bi-Concave Lens, 25.4 mm Diameter, -100 mm EFL, 1000-1550nm	11	11 Weeks	62	$62.00	ADD
KBC037AR.33	BK 7 Bi-Concave Lens, 25.4 mm Diameter, -100 mm EFL, 1064nm	11	11 Weeks	84	$84.00	ADD
KBC040	BK 7 Bi-Concave Lens, 25.4 mm Diameter, -75 mm EFL, Uncoated	0	In Stock	35	$35.00	ADD
KBC040AR.14	BK 7 Bi-Concave Lens, 25.4 mm Diameter, -75 mm EFL, 430-700nm	0	In Stock	52	$52.00	ADD
KBC040AR.16	BK 7 Bi-Concave Lens, 25.4 mm Diameter, -75 mm EFL, 650-1000nm	0	In Stock	62	$62.00 $68.00	ADD
KBC040AR.18	BK 7 Bi-Concave Lens, 25.4 mm Diameter, -75 mm EFL, 1000-1550nm	11	11 Weeks	62	$62.00	ADD
KBC040AR.33	BK 7 Bi-Concave Lens, 25.4 mm Diameter, -75 mm EFL, 1064nm	11	11 Weeks	84	$84.00	ADD
KBC043	BK 7 Bi-Concave Lens, 25.4 mm Diameter, -50 mm EFL, Uncoated	0	In Stock	35	$35.00	ADD
KBC043AR.14	BK 7 Bi-Concave Lens, 25.4 mm Diameter, -50 mm EFL, 430-700nm	0	In Stock	52	$52.00	ADD
KBC043AR.16	BK 7 Bi-Concave Lens, 25.4 mm Diameter, -50 mm EFL, 650-1000nm	0	In Stock	59	$59.00 $69.00	ADD
KBC043AR.18	BK 7 Bi-Concave Lens, 25.4 mm Diameter, -50 mm EFL, 1000-1550nm	0	In Stock	59	$59.00	ADD
KBC043AR.33	BK 7 Bi-Concave Lens, 25.4 mm Diameter, -50 mm EFL, 1064nm	0	In Stock	84	$84.00	ADD
KBC046	BK 7 Bi-Concave Lens, 25.4 mm Diameter, -25 mm EFL, Uncoated	8	8 Weeks	37	$37.00	ADD
KBC046AR.14	BK 7 Bi-Concave Lens, 25.4 mm Diameter, -25 mm EFL, 430-700nm	0	In Stock	50	$50.00 $55.00	ADD
KBC046AR.16	BK 7 Bi-Concave Lens, 25.4 mm Diameter, -25 mm EFL, 650-1000nm	0	In Stock	59	$59.00 $71.00	ADD
KBC046AR.18	BK 7 Bi-Concave Lens, 25.4 mm Diameter, -25 mm EFL, 1000-1550nm	11	11 Weeks	62	$62.00	ADD
KBC046AR.33	BK 7 Bi-Concave Lens, 25.4 mm Diameter, -25 mm EFL, 1064nm	11	11 Weeks	84	$84.00	ADD
KBC070	BK 7 Bi-Concave Lens, 50.8 mm Diameter, -500 mm EFL, Uncoated	0	In Stock	47	$47.00	ADD
KBC070AR.14	BK 7 Bi-Concave Lens, 50.8 mm Diameter, -500 mm EFL, 430-700nm	0	In Stock	95	$95.00	ADD
KBC070AR.16	BK 7 Bi-Concave Lens, 50.8 mm Diameter, -500 mm EFL, 650-1000nm	11	11 Weeks	105	$105.00	ADD
KBC070AR.18	BK 7 Bi-Concave Lens, 50.8 mm Diameter, -500 mm EFL, 1000-1550nm	0	In Stock	105	$105.00	ADD
KBC070AR.33	BK 7 Bi-Concave Lens, 50.8 mm Diameter, -500 mm EFL, 1064nm	0	In Stock	136	$136.00	ADD
KBC073	BK 7 Bi-Concave Lens, 50.8 mm Diameter, -250 mm EFL, Uncoated	0	In Stock	47	$47.00	ADD
KBC073AR.14	BK 7 Bi-Concave Lens, 50.8 mm Diameter, -250 mm EFL, 430-700nm	0	In Stock	95	$95.00	ADD
KBC073AR.16	BK 7 Bi-Concave Lens, 50.8 mm Diameter, -250 mm EFL, 650-1000nm	11	11 Weeks	105	$105.00	ADD
KBC073AR.18	BK 7 Bi-Concave Lens, 50.8 mm Diameter, -250 mm EFL, 1000-1550nm	11	11 Weeks	105	$105.00	ADD
KBC073AR.33	BK 7 Bi-Concave Lens, 50.8 mm Diameter, -250 mm EFL, 1064nm	0	In Stock	136	$136.00	ADD
KBC076	BK 7 Bi-Concave Lens, 50.8 mm Diameter, -200 mm EFL, Uncoated	7	7 Weeks	47	$47.00	ADD
KBC076AR.14	BK 7 Bi-Concave Lens, 50.8 mm Diameter, -200 mm EFL, 430-700nm	0	In Stock	91	$91.00	ADD
KBC076AR.16	BK 7 Bi-Concave Lens, 50.8 mm Diameter, -200 mm EFL, 650-1000nm	0	In Stock	105	$105.00	ADD
KBC076AR.18	BK 7 Bi-Concave Lens, 50.8 mm Diameter, -200 mm EFL, 1000-1550nm	11	11 Weeks	109	$109.00	ADD
KBC076AR.33	BK 7 Bi-Concave Lens, 50.8 mm Diameter, -200 mm EFL, 1064nm	0	In Stock	130	$130.00	ADD
KBC079	BK 7 Bi-Concave Lens, 50.8 mm Diameter, -150 mm EFL, Uncoated	0	In Stock	47	$47.00	ADD
KBC079AR.14	BK 7 Bi-Concave Lens, 50.8 mm Diameter, -150 mm EFL, 430-700nm	0	In Stock	91	$91.00	ADD
KBC079AR.16	BK 7 Bi-Concave Lens, 50.8 mm Diameter, -150 mm EFL, 650-1000nm	0	In Stock	106	$106.00	ADD
KBC079AR.18	BK 7 Bi-Concave Lens, 50.8 mm Diameter, -150 mm EFL, 1000-1550nm	11	11 Weeks	105	$105.00	ADD
KBC079AR.33	BK 7 Bi-Concave Lens, 50.8 mm Diameter, -150 mm EFL, 1064nm	11	11 Weeks	130	$130.00	ADD
KBC082	BK 7 Bi-Concave Lens, 50.8 mm Diameter, -100 mm EFL, Uncoated	0	In Stock	47	$47.00	ADD
KBC082AR.14	BK 7 Bi-Concave Lens, 50.8 mm Diameter, -100 mm EFL, 430-700nm	11	11 Weeks	95	$95.00	ADD
KBC082AR.16	BK 7 Bi-Concave Lens, 50.8 mm Diameter, -100 mm EFL, 650-1000nm	11	11 Weeks	107	$107.00	ADD
KBC082AR.18	BK 7 Bi-Concave Lens, 50.8 mm Diameter, -100 mm EFL, 1000-1550nm	0	In Stock	105	$105.00	ADD
KBC082AR.33	BK 7 Bi-Concave Lens, 50.8 mm Diameter, -100 mm EFL, 1064nm	0	In Stock	130	$130.00	ADD
KBC085	BK 7 Bi-Concave Lens, 50.8 mm Diameter, -75 mm EFL, Uncoated	0	In Stock	47	$47.00	ADD
KBC085AR.14	BK 7 Bi-Concave Lens, 50.8 mm Diameter, -75 mm EFL, 430-700nm	11	11 Weeks	95	$95.00	ADD
KBC085AR.16	BK 7 Bi-Concave Lens, 50.8 mm Diameter, -75 mm EFL, 650-1000nm	0	In Stock	105	$105.00	ADD
KBC085AR.18	BK 7 Bi-Concave Lens, 50.8 mm Diameter, -75 mm EFL, 1000-1550nm	11	11 Weeks	105	$105.00	ADD
KBC085AR.33	BK 7 Bi-Concave Lens, 50.8 mm Diameter, -75 mm EFL, 1064nm	0	In Stock	134	$134.00	ADD

Newport Resource e-Catalogs *

*e-Catalog pages include the most current information available at the time of printing.

BK 7 Precision Bi-Concave Lenses

Specifications

Substrate Specifications Table

Antireflection Coatings

Newport Resource e-Catalogs *

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