Lens system for wavefront modulation
An objective lens system comprises a set of lenses, arranged along a common optical axis to form a back focal plane. The objective lens system is a component in a microscope. The objective lens system also comprises an optical mask at the back focal plane, and a housing encapsulating the set of lenses and the optical mask.
1 . An objective lens system, comprising:
a set of lenses, arranged along a common optical axis to form a back focal plane;
an optical mask at said back focal plane, said optical mask being selected to extend a characteristic depth of field (DOF) of said set of lenses; and
a housing encapsulating said set of lenses and said optical mask;
wherein the objective lens system is a component in a microscope and is characterized by a depth of field of at least 4 μm for NA of about 1.49 oil immersion objective, or at least 6 μm for NA of about 1.35 silicon oil objective, or at least 20 μm for NA of about 0.75 air objective, or at least 50 μm for NA of about 0.3 air objective.
2 . The system according to claim 1 , wherein said optical mask is selected to encode depth information in an optical beam received from an object.
3 . The system according to claim 1 , wherein said optical mask is selected to encode spectral information in an optical beam received from an object.
4 . The system according to claim 1 , wherein said optical mask is selected to encode orientation information in an optical beam received from an object.
5 . The system according to claim 1 , wherein said optical mask is selected to introduce optical aberrations to an optical beam passing therethrough.
6 . The system according to claim 1 , wherein said optical mask is a phase mask.
7 . The system according to claim 1 , wherein said optical mask is an amplitude mask.
8 . The system according to claim 1 , wherein said optical mask is a phase-amplitude mask.
9 . The system according to claim 1 , comprising a removable ring holder, wherein said optical mask is mounted on said removable ring holder.
10 . The system according to claim 1 , characterized by a numerical aperture of at least 0.1.
11 . The system according to claim 1 , having a total length of less than 10 cm.
12 . A kit, comprising a plurality of objective lens systems, wherein each objective lens system comprises the system according to claim 1 , and wherein at least two of said objective lens system have different optical masks.
13 . A method of imaging an object, the method comprising:
selecting from the kit of claim 12 an objective lens system, based on at least one property of the object;
mounting said selected objective lens system on a microscope having an imaging system;
imaging the object using said imaging system; and
processing image data received from said imaging system to provide an image of the object.
14 . The method according to claim 13 , wherein said microscope is devoid of an active optical mask at a Fourier plane thereof.
15 . The method according to claim 13 , wherein said microscope is devoid of any optical mask aside for said optical mask at said objective lens system.
16 . A microscope system, comprising an objective lens system, a tube lens system, and an imaging system, wherein said objective lens system comprises the system according to claim 1 .
17 . A method of fabricating the objective lens system of claim 1 , the method comprising:
mounting said optical mask on a ring holder;
placing said ring holder at a back focal plane of said set of lenses arranged along said common optical axis; and
adjusting alignment of said ring holder to ensure that an optical axis of said optical mask is collinear with said common optical axis of said set of lenses.
18 . An optical mask system, comprising a ring holder and an optical mask mounted on said ring holder, said ring holder being removably connectable to a turret of a microscope in a manner that allows said turret to also receive, on top of said ring holder, the objective lens system of claim 1 .